The answer is in thermodynamics and kinetics. These two are arguably the most important concepts to grasp in chemistry.

But sometimes, even after several years of basic chemistry education, it is not easy to form a clear picture on how they govern reactivity!

Tutorial Review: Contents and Introduction

In this tutorial, we will try to introduce and summarize what these two concepts are, and their implications in chemical reactivity. This is obviously an introduction, intended for chemistry students of all levels.

For sure, there are more comprehensive explanations out there, and if you want one, go grab any of the best-known general chemistry books, or a more specific organic chemistry textbook. However, we have found that there are not many short explanations out there available for the general scientific public. This is somehow worrying, since, without a basic understanding of thermodynamics and kinetics, there is no way to understand the basic principles of reactivity. And without understanding reactivity, you are missing out on the most important part of chemistry.

But if you really want to dive on physical chemistry concepts as such, unfortunately you will find that most books can be impenetrable without a basic understanding of maths, physics and chemistry itself.

This is what we want to fix with this short tutorial. To give you a general overview on why chemical compounds react. We want to break the gate-keeping that has always been going on with physical organic chemistry!

As mentioned, this is intended to be brief. We will start off with the basic definitions, and hopefully make you go all the way through to understanding free-energy profiles of catalytic reactions.

Interested yet? Keep reading!

• A quick disclaimer: Since my background is in organic chemistry, I will base the explanations on simple organic chemical reactions, but most of the general principles apply to any kind of chemical reactivity.
• For most energy diagrams, the energy values are orientative, made up in order to explain the concepts.

Thermodynamics: The Energetic Stability of Molecules

Thermodynamics is the branch of physics that deals with heat, work and temperature, and their relation to energy, radiation, and physical properties of matter.

That is the definition of thermodynamics. As you can see, it is an incredibly broad concept. Let’s forget about it for now. How does thermodynamics dictate why do chemicals react?

Well, imagine every different molecule having an associated value for energy.

Some molecules will have larger energies and some others lower energies. Then consider that every chemical system has the tendency to go towards the point of lowest energy possible, in effect, the most stable point. This means that a molecule with high energy (less stable) will have a tendency (or “will want to react”) to transform into another molecule with lower energy (more stable).

Why is that? Because the process of going from a high energy state to a lower energy state releases energy, or heat, in what is called an exothermic process. This is what we call a thermodynamically-favored process, and it is basically what the laws of thermodynamics are telling us.

Thermodynamic Stability in Energy Diagrams

This is easier than it might sound. The image below illustrates what you just read. Molecule A can react in two ways: Absorbing heat it can be transformed into 1. Alternatively, it can evolve into 2 by releasing energy, in a thermodynamically-favorable manner. Of course, if these were the only two possible scenarios, all molecules of A would react to give 2, and stay there forever. But the picture is usually not that simple, and we will come back to this later.

You might be looking at the picture above and still not get what we mean by higher or lower energy. Let me redraw it in a way you will probably have seen elsewhere, or been taught in school/college:

The scheme above resembles what you are always taught in introductory organic chemistry courses: more substituted isomers of alkenes are more stable (A and 2 vs. 1) and trans isomers are more stable than cis isomers (2 vs A).

What does this means? It means that, given the appropriate circumstances or conditions, both 1 and A would like to react to give 2. But we now that less stable alkenes such as 1 are perfectly inert, and can be handled and stored without worries. So, what is the deal here?

The answer is kinetics and activation barriers.

Kinetics: The Barriers of Chemical Reactivity

Before diving into kinetics, let me present another quick example of a thermodynamically-favorable process. An energy diagram of an Sn2 substitution reaction in this case.

As you can see, if we set the zero in energy for a hydroxyde anion plus a chloromethane molecule (in energy diagrams you always set an energy for the whole system, not individual molecules), the total energy of the products of the corresponding Sn2 reaction (tert-butyl alcohol and a chloride anion) will be lower (about 20 kcal/mol lower!).

What does this mean? That the reaction is thermodynamically favorable, and in principle it will not take place the other way around.

But does this mean that, mixing hydroxide with chloromethane at any temperature will lead to the immediate formation of tert-butyl alcohol and chloride? Of course not! The rate at which the reaction proceeds will depend directly on the temperature, and if the temperature is low enough, the reaction will not take place at all, even though the process is thermodynamically favorable.

Why is that? Kinetics is the answer.

What Are Chemical Reaction Kinetics?

Chemical or reaction kinetics is the branch of physical chemistry that studies the rates (or speeds) of chemical reactions.

In summary, thermodynamics determines in what direction a chemical reaction proceeds, and kinetics determines the speed or rate at which that process occurs.

Of course, in the last scheme of the previous section, there was something missing. In a chemical reaction, reactant A does not simply transform into product B. Reactions take place through what we call transition states.

Transition states are intermediate structures between reactants and products of a chemical reaction step. They are usually higher in energy (less stable) than both the reactants and the products, and the energy difference between the reactants and the transition states, also known as activation energy, is the barrier necessary to overcome for a thermodynamically-favorable reaction to take place.

Why Do Chemicals React? Thermodynamics and Kinetics Combined

See below a now complete version of the free-energy diagram of the Sn2 substitution reaction. As you can see, the process is thermodynamically favorable, but a barrier or activation energy of 23.0 kcal/mol has to be overcome in order to reach the products.

The larger the activation energy, the lower the speed or rate of a reaction at any given temperature. Usually, we set a limit of barriers of around 25 kcal/mol for reactions to proceed at a significant rate (this is, in several hours or days) at 25 ºC. Easy enough to remember.

Stability vs Inertness

No matter how thermodynamically favorable a process is, if the barriers to reach the corresponding transition are too high (say, higher than 30-40 kcal/mol), that chemical reaction is not going to take place under regular conditions.

This allows us to make a clarification between stability and inertness as properties of chemicals.

Stability is a thermodynamic concept, while inertness is a kinetic concept.

• A compound is stable, if it is relatively low in energy (compared to the molecules to which it may interconvert into). The opposite would be unstable, high in energy.

• On the other hand, we say that a compound is kinetically inert if in order to react it has to overcome large activation barriers.

A compound can be both unstable and inert. That is why we can handle and store thermodynamically unstable primary alkenes such as 1-propene without them isomerizing to more-stable secondary alkenes such as cis- or trans-2-propene (see the first two schemes).

But we can trick kinetics! Catalysts can be used to lower the activation energy of chemical transformations, allowing them to proceed more rapidly, or simply to proceed at all!

• Note: Theoretically, no matter how high the activation energy of a process might be, we say that it is always taking place at a certain rate. However, if the energy barriers are higher than, say, 50 kcal/mol, the rate or speed of the reaction would be so low that it would take many many years before we can detect a significant conversion.

Catalysis: Lowering the Barrier!

Now that we know why chemicals react, let me explain how we chemists try to override the system and make activation barriers lower.

A catalyst is a chemical entity (a molecule, a salt, a coordination complex…) which speeds up a chemical reaction. It also can unlock new reactivity pathways and make reactions work that would not be possible otherwise.

Let’s take a specific classical example. The electrophilic aromatic substitution of benzene with molecular bromine (Br–Br). This reaction is traditionally carried out using a Lewis acid as catalyst, such as iron tribromide.

But let us imagine first a catalyst-free version of the process, which I am certain can occur if you mix together benzene and bromine, and heat it up enough.

How Thermal, Catalyst-Free Reactions Occur

The first step of this reaction is the formation of the well-known Wheland intermediate. An intermediate (not to be confused with a transition state, which rather connects intermediates together) is a reactive chemical species which is formed in one of the steps in the middle of a chemical reaction of A leading to B, as intermediate point. For benzene to be transformed into bromobenzene, it has to pass through this intermediate species. Intermediates can rarely be isolated, since they usually are both thermodynamically unstable and kinetically reactive.

In any case, the reactants have to overcome a high activation barrier of 30 kcal/mol. Once the temperature is enough for this to take place, the rest of the process has lower activation barriers, and takes place downhill to give reaction products in an overall thermodynamically favorable process (exothermic by -11 kcal/mol).

But we can speed things up with a catalyst!

Lewis Acid-Catalyzed Electrophilic Aromatic Substitutions

By adding a catalyst to the mixture, we can access new transitions states, which are more stable, and hence lower in energy. And what happens when the transition state of the rate-limiting step of a reaction is lower in energy? That the activation barrier of the whole process is much lower!

This is basically the role of FeBr₃ (the catalyst) of this reaction: stabilizes transition states and intermediates. Now the activation barrier to reach the first transition state is much lower (20 vs 30 kcal/mol), allowing the reaction to take place under mild conditions.

Also, note that FeBr₃ is recovered unreacted with the products. This is another feature of catalysts: they can be recovered and re-enter another reaction cycle. This is why they are often employed in sub-stoichiometric amounts (this is, less than one mole of catalyst is enough to drive full conversion of one mole of starting material).

But as we have already mentioned, thanks to catalysis we not only can lower activation barriers that would need totally unpractical temperatures. We can also unlock reactions that would take hundreds of years to complete by themselves. We can also achieve completely new selectivities, and develop new chemical processes.

I work in catalysis myself, and I can tell you this is one of the most important, exciting and active fields of chemistry.

This is the end of this tutorial review, and I hope it has helped you to get a clearer picture of why chemical reactions take place and what leads chemicals to react. We certainly covered concepts you have to master if you are learning chemistry at any level!

The post Why Do Chemicals React? Kinetics and Thermodynamics appeared first on Chemistry Hall.

What Is the Swern Oxidation?

The Swern oxidation is the oxidation of a primary or secondary alcohol to an aldehyde or a ketone, respectively, by the combination of oxalyl chloride and dimethylsulfoxide followed by triethylamine.

Discovery and Applications

The Swern oxidation was first discovered by Daniel Swern and Kanji Omura in 1978. From this point, this methodology evolved into one of the most used strategies to oxidize both secondary and primary alcohols to ketones or aldehydes, respectively.

In this reaction, dimethylsulfoxide (DMSO) acts as the effective oxidizing agent, getting reduced to dimethylsulfide (DMS) as a consequence. However, DMSO by itself is not reactive enough to take part in this redox process, it needs to be activated by oxalyl chloride, (CO)₂Cl₂. This results in the formation of an adduct that can evolve into the corresponding ketone or aldehyde by action of a base (generally triethylamine), upon release of CO, CO₂, and dimethylsulfide (SMe₂), through a beautiful mechanism that is a must know for any student of organic chemistry.

This reaction has distinctive features that make it extremely popular among synthetic chemists.

Advantages and Drawbacks

One of the best features of this oxidation method is that it does not further oxidizes aldehydes to carboxylic acids, so a single 2-electron oxidation of primary alcohols can be achieved. This is often not the case with, for instance, metal-based oxidations, such as the use of potassium permanganate. Other alternatives that stop at the aldehydes, such as DMP, are usually much more expensive than the simple reagents required for the Swern.

This reaction often proceeds smoothly at very low temperatures. The usual procedure is run at -78 ºC, which means that the reaction conditions are extremely mild, this usually leads to very selective procedures that usually don’t harm other functional groups of complex molecules. On the other hand, this can also be considered a small inconvenience, since it requires setting up an acetone-dry ice bath (-78 ºC) or the use of a cryocooler instrument.

There are not many disadvantages for this reaction, as evidenced by how it has withstood the test of time, but the more characteristic one is on of the side products: dimethylsulfide is a nasty smelly gas! Make sure to run the reaction in a well-ventilated fumehood.

The Mechanism of the Swern Oxidation

The mechanism of this oxidation starts by the activation of the oxidant (DMSO) by oxalyl chloride. This generates an adduct upon release of a chloride anion. This chloride anion acts then as nucleophile towards the electrophilic sulfur atom, which makes the intermediate collapse. This results in the release of a molecule of CO₂ and a molecule of CO. This results in the formation of Me₂Cl₂S, and highly activated oxidizing agent.

This Me₂Cl₂S intermediate can react with primary and secondary alcohols to give the adduct shown below. Then, this adduct can be deprotonated by an organic base (triethylamine) to give a sulfur ylide, upon release of triethylammonium chloride.

Finally, this ylide intermediate evolves through a 5-membered cyclic transition state to release dimethylsulfide (DMS) and the resulting oxidized product (an aldehyde or ketone).

How Do You Run a Swern Oxidation in the Lab?

As someone who has run this oxidation at work many times myself, here is a general illustration of the practical procedure for this reaction.

Finally you can further purify the product if it is required by flash column chromatography, and you are all done1

The post The Swern Oxidation: Mechanism and Features appeared first on Chemistry Hall.

For many students, video content is a useful tool to supplement classroom learning and review concepts. At Crash Course, we create free online video courses on Youtube focused on a wide variety of subjects, from literature to chemistry. Over the past few months we have been making a new series of videos that are being uploaded weekly. Here you can find the presentation video and the YouTube channel:

The first part of the series is focused on the tools that help us understand organic chemistry, things like bonding, structure, and naming molecules. Once we have a basic toolbox, we start building molecules: from small molecules like ethanol to giant macromolecules like high-density polyethylene. In the second half of the course, we will get into multi-step synthesis of larger molecules. We’ll also look at important developments in the pharmaceutical industry because understanding organic chemistry is important in understanding health, medicine, and how the biochemistry of the body works. 

If this course sounds like a useful tool for your classroom or learning, you may also want to check out the Crash Course App (Google Play link here)! The app offers flashcards with review questions for each video in the organic chemistry series. 

If you’re interested in learning more about how a course like this is built and written, below is a message from the Content Manager of Crash Course, Ceri Riley, as well as a script excerpt.

A Presentation by the Content Manager of Crash Course

When I took Organic Chemistry in college, it was incredibly tricky to wrap my brain around substitution reactions. I relied heavily on memorization, and even then, when it came time to solve problems, I felt like I was guessing when it came to SN1 and SN2 mechanisms. I’m really glad our expert consultant, Dr. Kristen Procko, decided to break substitution reactions into two episodes. And in this introductory episode, there are a few helpful logical breakdowns of the differences between SN1 and SN2, from using general models, to playground metaphors, and specific examples. 

Sharing CC Organic Chemistry scripts feels definitely like sharing a rough draft, because Deboki Chakravarti’s performance as host and Thought Cafe’s animations add SO MUCH to this series. It’s one thing to see a reaction mechanism in a textbook or in a script, and it’s another to see it fully animated. That being said, it takes a team of experts to get all these small details right: we have a consultant, writer, and fact checker. This is one of the biggest content teams we’ve ever had, and it’s partially because there are so many tiny things to get right, from subscripts to spelling to making sure our logic is clear and we’re giving as many tips as possible to help students with this difficult material. 

Hopefully this excerpt sheds some light into our scripting process and gives a sneak peak at some reactions we’re going to learn in a few months on the channel. I’m really proud of how much we packed into this episode (and honestly, all of these episodes) and hope they help many people in the upcoming months and years! 

– Ceri Riley, script editor of CC Orgo and content manager of Crash Course

Script Excerpt of CCORG20: Intro to Substitution Reactions

In general chemistry, you might’ve heard substitution reactions called displacement reactions. Like two pairs of dance partners, two ionic compounds in water could swap ions when mixed, so the positive part of one compound ended up with the negative of the other. 

In organic chemistry, substitution reactions also involve switching partners, but they’re a little more complicated. We usually deal with single displacement reactions, where one group finds a new partner and the other has to… just… leave. And organic molecules are a bit more complicated than inorganic ions, so we’ll have to think carefully about stereochemistry. 

Don’t worry though. We got this. To help us figure out organic substitution reactions, we need three things:

Number 1:  A molecule containing an sp³-hybridized carbon, which we’re going to call the substrate. This sp³-hybridized carbon will have a leaving group attached to it.

Number 2:  That leaving group, which is an atom or group that can accept electron density, and stabilize the negative charge that will hold after “leaving” the substrate.

And Number 3:  A nucleophile, which is an atom or functional group that contains a lone pair or a pi bond, and is electron-rich by nature.

This is the general model of a substitution reaction, with placeholders. 

We can add in some real atoms and molecules here: the substrate is 1-bromobutane, which switches its bromide dance partner for hydroxide. In this reaction, the leaving group is a bromide ion, and the nucleophile is a hydroxide ion.

The Mechanisms of Substitution Reactions

As we’ve been discovering, organic chemistry is full of puzzles, so substitution reaction mechanisms can get a little tricky. Specifically, they can take two paths called S_N1 and S_N2. Depending on the path, we’ll see differences in stereochemistry and mechanism. 

Let’s adventure along one pathway, or one mechanism, at a time. And we’ll start with S_N1. The S is for substitution, the N is for nucleophilic, and the 1 is for unimolecular, which tells us about the reaction rate. 

There are two steps to an S_N1 reaction: formation of a carbocation and nucleophilic attack. To see what this looks like in a reaction mechanism, let’s use a general model again.

First, formation of the carbocation is the rate-determining step. We’ve got to wait for that  leaving group to pop off of the molecule with its electrons and give the carbon a positive charge. 

Since this could take awhile, we say this first process is the rate-determining step, or the slow step of the entire reaction. And the reason we call S_N1 reactions unimolecular is because the overall rate of this reaction depends on that one molecule, the substrate, losing its leaving group.

Okay, I know we can broadly visualize substitutions as dancing, but I like to picture the details with a playground. Specifically, a merry-go-round — you know, those spinny platforms where you sit and someone else pushes it in circles until you’re super dizzy? Suppose there was a merry-go-round that could only hold three kids. You’re the fourth, so you get stuck spinning your friends, waiting for one to get off so you can hop on. It always feels like forever before you get a turn. But that’s basically the first step of an S_N1 reaction.

Now, a carbocation is pretty irresistible to nucleophiles, so next the nucleophile attacks this intermediate and a bond is formed. Sort of like how you’d quickly jump onto a merry-go-round to take a turn when your friend finally hops off. Because it happens so quickly, this step does not determine the overall rate.

Moving on to S_N2 Reactions

Those were the basic steps along the S_N1 pathway… But in an S_N2 mechanism, the S is for substitution, the N is for nucleophilic, and the 2 is for bimolecular – because the reaction rate will depend on two molecules coming together, instead of one just falling apart. Our two molecules are the substrate and the nucleophile. 

In an S_N2 mechanism, there is no carbocation intermediate and the nucleophile plays a much more active role. It all happens in one big, dramatic swoop: the nucleophile does a backside attack, pushes out the leaving group, and the stereochemistry gets inverted….kind of like an umbrella that gets turned inside-out in a heavy wind storm.  

Specifically, it’s another one of those funky concerted reactions where bonds break and form at the same time. S_N2 mechanisms go through a stage that looks like a carbon with five bonds. But it’s not, because both the nucleophile and leaving group are attached with partial bonds. 

A partial bond means as one bond is forming, the other is breaking. Basically, the nucleophile starts to share its electrons but doesn’t want to fully commit until the leaving group leaves. And the substrate doesn’t want to fully let go of the leaving group until the nucleophile commits. Kind of like a passionate ballet with dancers joining hands or letting go. 

Or, going back to our merry-go-round metaphor, it’s like you’re spinning three friends again. But instead of waiting patiently for one of them to hop off, you push one friend away and sit down across from where they were. Then your other friends, to balance it out (or just to get away from you) shift over. S_N2 is a much rowdier playground than S_N1!

The post A Journey into Substitution Reactions by Crash Course appeared first on Chemistry Hall.

Well, the chemical difference is not the one you hear on the news which distinguishes “organic” vegetables from “non-organic” ones. Guess what, both are made up of organic and inorganic compounds.

Let’s say that the “agriculture industry” definition is not the same as the chemical definition. In chemistry, there is a major difference, which is well defined.

Telling the difference between organic and inorganic compounds is one of the main things you need to make clear while learning chemistry. If you are interested, learn more about thermodynamics and kinetics, another two of thee most important concepts in chemistry.

In this article we will explain it in detail, so at the end you will be able to differentiate both of types of chemicals without any difficulty. We will try to solve all your doubts about this eternal chemistry question!

In the early days, scientists separated organic and inorganic compounds on the fact that the first group was considered as a result of the activity of living beings, whereas the second group belonged to the processes unrelated to any way of life. Now there are much clearer definitions.

Introduction

About 200 years ago, at the transition between alchemy and chemistry, chemists classified the chemical compounds into two main groups.

1. Organic Compounds

An easy, layman-friendly definition for organic compounds is that those are the ones which are derived from living things such as plants and animals are known as organic compounds like sugars, lipids, proteins, nucleic acids, etc.

More strictly speaking, we consider a compound to be organic if it is made of carbon atoms which participate in covalent bonds. Generally (but not always), organic compounds also present covalent C–H bonds.

2. Inorganic Compounds

An easy definition for an outsider, is that those compounds which are obtained from non-living things or mineral sources are known as inorganic compounds like NaCl (table salt) and NaHCO₃, (baking soda), etc.

Defining inorganic compounds is pretty easy after having defined organic compounds. As a rule, every chemical that does not fall into the category of “organic”, is considered an inorganic compound.

The Vital Force Theory and the First Chemical Total Synthesis

Let’s go back in time once again, to the very early days of chemistry. The theory known as the “vital force theory” might ring a bell to you if you are familiar with the history of chemistry.

This theory was proposed by Swedish chemist Berzelius in 1815. This theory states that organic compounds can’t be synthesized in a laboratory. Early chemists believed that organic compounds could only be obtained from living organisms, through “vital forces”. That is why this theory is referred to as “vital force theory”.

In 1828, Friedrich Wohler, a German chemist, synthesized urea in the laboratory. This accounts for the first chemical total synthesis of a natural organic compound ever!

This accomplishment showed that it was possible to synthesize an organic compound (urea), starting from an inorganic compound (ammonium cyanate), in the laboratory: treating silver cyanate with ammonium chloride afforded a crystalline compound that was found to be identical to urea isolated from urine.

This chemical transformation invalidated the vital force theory, and soon after this, chemists began to make organic compounds in the laboratory. Hence the modern definition of organic compounds was introduced in the scientific world. This also marks the very beginning of organic chemistry as a discipline.

The Modern Definitions

Organic Compounds

The compounds which contain carbon atoms as main constituent, which are bonded together through covalent bonds, are called organic compounds. Most organic compounds also contain hydrogen. Other common elements present in organic compounds are oxygen, nitrogen, sulphur, halogens, or phosphorous. But those are not the only ones.

In most cases, all atoms of the different elements are held together through covalent bonds. Some exceptions would be, for example, organic carboxylates, or ammonium salts. But you could argue that those are “inorganic salts of organic compounds”.

Some compounds that might sound “non-organic as hell” such as polymers (a fancy name for plastics), are actually long-chained organic compounds. An example is polystyrene. It’s backbone is basically all covalent C–C and C–H bonds.

Bear in mind that “organic compound” does not imply “biochemical compound”. On the other hand, the backbone of biochemistry is mostly organic compounds (although metals are extremely important in biological systems such as iron in hemoglobin).

Inorganic compounds

Take every organic compound out. You are left with inorganic compounds. If it doesn’t fall into the definition of organic, it is inorganic.

In general, the compounds which do not have C–C or C–H covalent bonds are called inorganic compounds.

There are many compounds that only have covalent bonds, they have carbon atoms, but are not organic compounds. Examples of this type of inorganic compounds include carbon monoxide, carbon dioxide, inorganic carbonates, carbides, etc. Notably, allotropes of carbon such as graphite, graphene or diamond, contain only carbon atoms, but are considered inorganic compounds.

As you can see, sometimes the definition is not so well established. In fact, I couldn’t really find a clear definition for both provided by IUPAC. This illustrates the fact that defining the line between inorganic and organic chemicals.

Some interesting examples of this middle ground are organometallic compounds. These are made up of an organic component, generally bound to an inorganic component through a carbon–metal bond. These are really fun and are one of the most widely explored research topics in modern chemistry!

Major Differences Between Organic and Inorganic Compounds

We will try to sumarize in a quick comparison table the key differences between organic and inorganic compounds.

However, bear in mind that in most cases these are just generalizations and won’t be true for any scenario, and definitely will have exceptions.

And as you can probably guess, the examples for both types of both types can go on forever.

Examples of Organic Compounds

Time to dive into learning organic chemistry! These are just some natural and non-natural examples of organic compounds.

Carbohydrates

These are commonly known as sugars. In terms of functional groups, these are aldehydes or ketones having additional hydroxyl groups. Carbohydrates are a simple way to illustrate organic compounds, since they are just chains of C–C and C–H covalent bonds in the company of some of the most typical organic functional groups (alcohols and carbonyls). Examples of carbohydrates are glucose, fructose, sucrose, etc.

Proteins

Proteins are made up of chains of amino acids joined together to form peptides. Proteins are actually polymers, which can be made up of a single chain of many amino acids, or of several chains that are packed together by non-covalent interactions. Since they are made of amino acids, they contain carbon, hydrogen, oxygen, and also nitrogen atoms, everything held together by covalent bonds, and also non-covalent interactions. A classical example of proteins are enzymes.

Organic Solvents

Organic solvents are organic compounds which are commonly used to dissolve chemicals in the lab, mainly for setting up chemical reactions. “Like dissolves like” they say, so these solvents are a must for carrying out organic reactions. They are usually simple organic compounds made of carbon, hydrogen, and also oxygen or nitrogen, sometimes sulphur. They are usually liquids at room temperature and have boiling points ranging from 40 ºC to 200 ºC. Common examples are hexane, cyclohexane (CyH), acetone, tetrahydrofuran (THF), toluene (PhMe), ethanol (EtOH), methanol (MeOH), benzene (PhH), dimethylsulfoxide (DMSO) or dimethylformamide (DMF).

Whatever Organic Compound that You Can Imagine Making on an Organic Chemistry Lab

The only limit for organic compounds is the imagination of the chemist. Theres is most likely an infinite number of combinations in which you can arrange carbon and hydrogen atoms to form organic compounds. Not to mention other elements.

That’s something I just made up in less than 1 minute in ChemDraw, and it seems like a totally reasonable organic compound.

Examples of Inorganic Compounds

Getting ready to study the realm of inorganic chemistry? These are just some common examples of inorganic molecules.

NaCl – Sodium Chloride or Table Salt

The salt you use for cooking is mostly sodium chloride, NaCl, and this is the most classical example of an inorganic compound. Specifically, it’s an ionic compound composed of an equal number of sodium(I) cations and chloride anions, arranged though a symmetrical three-dimensional network.

Carbon dioxide

Carbon dioxide is another example of inorganic compound with a chemical formula CO₂.  Despite of the presence of carbon atom, CO₂ is considered an inorganic compounds because containing carbon and covalent bonds doesn’t directly make a compound organic. You need a C–H bond or an equivalent.

For example, carbon tetrachloride, CCl4, is considered an organic compound, because instead of C–H covalent bonds it has C–Cl bonds, which are electronically equivalent. The bonding model in carbon dioxide, carbon monoxide, and other small inorganic compounds is quite different.

Diamond and Graphite

Allotropes of carbon such as graphite, graphene or diamond are classified as inorganic compounds, even when they have

Example of an Organometallic Compound

Right in the middle of organic and inorganic compounds, we can find organometallic compounds, which are characterized by having a carbon–metal bond (which in many cases is a “hybrid” between a covalent and an ionic bond).

An example of this are Grignard reagents (such as phenyl magnesium bromide) or organolithium compounds (such as butyl lithium).

To Sum Up

I hope we managed to explain clearly the basic differences between organic and inorganic compounds.

Organic compounds always contain carbon atoms, and almost always hydrogen atoms, all of them held together by covalent forces.

Inorganic compounds are just the rest!

The post What Is the Difference Between Organic and Inorganic Compounds? appeared first on Chemistry Hall.

Especially in the most recent years, many conference lectures by the best research group leaders on chemistry are being recorded and posted publicly online, so everybody can enjoy them and learn about chemistry. All around the globe. Without the need to travel long distances.

Simply thinking about it is amazing! Who could have though that this would be possible >30 years ago. At that time, the possibility of even checking research papers online, did not exist. We did research without the aid of databases on the library.

Now you can access all research that has ever been published online. But not only that, you can also “assist to conferences virtually” from anywhere.

However, not only modern chemistry has been recorded. One of the greatest examples out there of online chemistry talks are the Woodward’s legendary lectures.

Woodward’s Organic Chemistry Lectures

R. B. Woodward won the Nobel prize in chemistry in 1965 for his achievements in the art and science of organic synthesis. In my opinion, he is the greatest organic chemist of all time. He could’ve gotten two more Nobel prizes if he didn’t die so young (1979, at 62), probably due to his contributions to the chemistry of metallocenes and to the Woodward-Hoffmann rules, among many others.

Anyway, he’s been known for giving epic hours-long lectures, explaining the details of his total synthesis. And some of these were filmed at the time! And now, thanks to the internet, are available to watch on YouTube. This is one example:

You can look for a couple more that are around the internet. Even if you are a young chemistry student, if you are interested in organic chemistry, you should take a look. Classical organic reactions that are employed in these >50 years old synthesis are the ones that are usually taught in undergraduate organic chemistry courses.

In any case, watching the master of organic chemistry is an incredible source of inspiration for any aspiring chemist.

The Best Conference Chemistry Lectures Online

As we already mentioned, more and more, we get big conference lectures tape recorded and posted online. These are some of the most enjoyable ones that we have found.

Baran’s Electrifying Chemistry

First off, you can watch and hour-long presentation on synthetic organic electrochemistry by Phil S. Baran, from Scripps Research.

In this lecture, he covers the main reasons behind how using electricity as oxidant/reductant, instead of a chemical reagent is the greenest possible approach for carrying out redox transformations.

New chemical reactivity is being unlocked month after month taking advantage of synthetic electrochemistry. Here, Baran summarizes how he and his research group are pursuing this field of chemistry. He also presents new IKA equipment for carrying out electrochemical transformations in a reproducible manner.

2018 Nobel Prize Frances Arnold

Frances Arnold, from Caltech, won the 2018 Nobel Prize in chemistry for her contributions to the field of directed evolution of enzymes. This lecture is from one year before, in a symposium called “Tailored Biology”.

Her ground-breaking research has to do with modifying enzymes, to make them catalyze chemical transformations that they would not promote naturally, or at least not as selectively.

John Goodenough’s Nobel Prize Press Conference

John Goodenough, a chemistry professor at the University of Texas (Austin), and he is the oldest Nobel laureate of all time!

Prof. Goodenough got his Nobel Prize in chemistry in 2019, as a recognition of his contributions on the development of lithium-ion rechargeable batteries. What’s to say about this discovery? All of us use rechargeable batteries on a daily basis, all the time. We cannot imagine a world without them right now. And one of the main responsible people for these advances is this man. Here’s his Nobel press conference:

The Magic of Chemistry by David Leigh

In 2016, the Nobel prize in chemistry was awarded jointly to Ben Feringa, Fraser Stoddart, and Jean-Pierre Sauvage. They got it for their work on molecular machines, an exploding and revolutionary field within supramolecular chemistry.

Arguably, the fourth key player on this field is David Leigh. He also works on molecular machines. But his lectures are best-known for his personal touch. He is also a professional magician, and brings magic tricks to the chemistry lectures. Apart from presenting some amazing research, the magic makes these lectures some of the best in the world. And you can enjoy and watch one of these online chemistry lectures right now.

The Best Educational Chemistry Lectures

Besides top-tier ground-breaking research conference lectures, you can also enjoy and learn form some more educational resources.

Some More Magical Chemistry

Some of the most both educational and entertaining videos that you can find online on chemistry are the ones by Andrew Szydlo.

He goes though color and phase changes, and he leads students through the world of “playing tricks” with molecules. This might seem like a long video, but I assure you, if you decide to start to watch it, make sure that you don’t have anything to do for the following hour-and-a-half!

Walter Lewin’s Physics Lectures

So we are past chemistry for this video. But I bring it to your attention for two reasons:

• Chemistry and physics are heavily packed together.
• The lectures by MIT professor Walter Lewin are just fantastic, the best educational videos I have ever watched online.

To be fair, when I started studying some physics in college, I didn’t enjoy them that much. That was until I found Lewin’s lectures online. This made love physics almost as much as chemistry.

MIT Lectures from Your Couch

Who said that not anyone in the world can take chemistry lectures from MIT? Now it is completely possible with this and other courses on chemistry offered by this prestigious institution.

Here, this solid state chemistry course is a brilliant example of some of the best online chemistry lectures from a purely educational point of view.

General Chemistry Online Lecture Series (UCI)

This is another example, this time brought to you by the OpenCourseWare of UC Irvine. This is one of the best educational series of lectures on general chemistry that you can watch online.

Periodic Videos!

Finally, we could not end this post with a mention to the Periodic Videos YouTube channel. Here, Sir Martyn Poliakoff and the rest of his team at the University of Nottingham, tackle the most exciting chemistry facts, experiments and questions. Here, every experiment that you alway wanted to perform, but couldn’t, is answered in these videos.

As the title of the site claims, they have covered the entire periodic table, with at least one video on each of the elements. Go on now and check the one for your favorite element!

Closing Up

As you can see, there is plenty of online chemistry lectures that you can explore throughout the internet. These are just some examples, but go ahead and find some more that fit your interests!

Finally, make sure to share your favorite chemistry lectures in the comment sections with us!

The post Watch The Best Online Chemistry Lectures From Your Coach appeared first on Chemistry Hall.

Perhaps some would argue that this Chemistry area is not as “cool” as others, but I am sure that those who agree with me will find plenty of reasons to support the beauty of analytical chemistry.

But in any case, it’s something really necessary, and for making the process of learning it easier, getting your hands on the best analytical chemistry textbook that you can find its key.

But… What Do Analytical Chemists Do?

Now I might have caught a bit your attention on the subject, but, what is exactly analytical chemistry? A dictionary definition would say:

“Analytical chemistry is a scientific discipline which develops and applies methods, instruments, and strategies to obtain information on the composition and nature of matter in space and time”.

Kellner, R. Analytical Chemistry 1994, 66, 99A–101A

Fancy, but maybe not very insightful for a beginner. Analytical chemistry deals essentially with three aspects: measurement, analysis, and information. That’s it! In analytical chemistry you measure (quantity, concentration, etc.) a chemical/biochemical substance, you analyze the results, and then you obtain useful information that can be used to solve a technical (or social) problem.

This process seems simple, but the importance can be huge. A good example is residual pesticides found in food, which must comply with stringent regulations that define acceptable limits (although some substances are totally forbidden) for their presence in food. Analytical chemists work all the time on problems like this, and we are grateful for that!

Not only that, chemist from other disciplines (physical, organic, inorganic) base their daily research and rely on results obtained from analytical techniques (such as GCMS or LCMS analysis).

More interested in analytical chemistry now? Great! the next step is to open a book and start reading. As in all fields of science, we always start from the basics before achieving mastery. Of course, with a good analytical chemistry book, the path is going to be even better, particularly if some of you have already experienced some problems learning analytical chemistry. 

Furthermore, if you are a professor looking to find the very best book to base your lectures on, we’ve got you covered too.

What is the Best Analytical Chemistry Textbook?

But, which book do we choose? What is the best analytical chemistry textbook? Don’t worry, in this review, we will help you to find exactly the textbook you need.

For starters, we are going to make it easy for you and disclose our preference as top pick, which is Quantitative Chemical Analysis by Daniel C. Harris. Even thought Skoog’s comes as second runner up, Harris’ is simply as good as it gets regarding analytical chemistry texts for college.

Harris Quantitative Chemical Analysis

We will now quickly summarize all the reviewed texts, and then go deep exploring the pros and cons of each of then on the specific reviews.

Quick Reference Table: Top 5 Analytical Chemistry Books

Complete Review of All Books

Harris Quantitative Chemical Analysis

Considered the gold standard for analytical chemistry, the Quantitative Chemical Analysis book by Daniel C. Harris (and Charles A. Lucy in the latest version) has been in the bookstores since 1982.

Harris Quantitative Chemical Analysis

A must-to-read book for anyone interested (grad or undergrad) in analytical chemistry, this book is easy to understand and contains several examples and problems that will make learning analytical chemistry a much friendlier experience. 

It will provide you with sound principles of analytical chemistry and will teach “How” and “Why” analytical chemistry should be applied in real-life situations.  You will also find this book very useful for learning instrumental analysis, being a great balance between readability for non-Chemistry majors and in-depth content for more advanced readers.

Being a very comprehensive book, you will find information from the basic statistics, through acid-base equilibria, titrations, to electrochemistry, spectroscopy, and chromatography. The use of suitable software is also encouraged and exemplified in most, if not all, topics. 

This book is written in a quite straightforward style that makes its content easy to follow and understand. Concepts are presented right away and succinctly explained. If you want direct answers to your questions, this is the book of choice.

Skoog Fundamentals of Analytical Chemistry

A book with a good price/quality ratio, although it is more suitable for readers already familiar with analytical chemistry topics. Written by Douglas A. Skoog, Donald M. West, F. James Holler, and Stanley R. Crouch, it is a readable and engaging book with well-explained examples that is a safe bet to learn the principles of analytical chemistry and much more.

Skoog Fundamentals of Analytical Chemistry

Being a very comprehensive book, it is also reinforced by multiple high-quality images and case studies that properly demonstrate the principles, importance, and applicability of analytical chemistry. Several questions and problems are also presented for readers to practice.

Interesting topics such as kinetics methods of analysis and supercritical fluid separations, which are not common among analytical chemistry textbooks, are also covered in this book. This is one of my favorite books in analytical chemistry, and for sure, the book I recommend on every chemist shelf.

Analytical Chemistry (Christian)

This book, authored by Gary D. Christian, Purnendu K. Dasgupta, and Kevin A. Schug, is already in the 7^th edition.

Analytical Chemistry (Christian)

Particularly designed for undergraduate students in fields related to chemistry, it contains the necessary techniques and principles related to quantitative and instrumental analysis. The book has a modern approach with a clear methodology and explanations. It is also very versatile, being useful as an introductory text for first courses in analytical chemistry or as a reference guide for practicing analytical chemists.

Nevertheless, the style of this book might result more difficult to follow, so some base of chemistry is advisable before start reading and practicing. Not a first-choice book for people from other fields adventuring into analytical chemistry for the first time.

Worth to mention: an entire section of the book is devoted to genomics and proteomics, making it very useful for analytical chemistry in biological applications.

Analytical Chemistry and Quantitative Analysis

David Hage and James Carr created a book with a contemporary approach, presenting practice and applications of today’s analytical chemistry.

Analytical Chemistry and Quantitative Analysis

Applications span from forensics to environmental analysis and pharmaceutical sciences, although other interesting topics are also approached. Ideal as an undergraduate quantitative analysis book, as well as an introductory book to the area.

Easy to follow, this book somewhat combines the material from the more comprehensive “Quantitative Chemical Analysis” and “Fundamentals of Analytical Chemistry” and put it in a clearer version.

Principles and Practice of Analytical Chemistry

The book, created by F.W. Fifield and David Kealey, is already in the 5^th edition. Recognized as a complete and useful reference manual, is another example of a particularly valuable analytical chemistry book for undergraduate students.

Principles and Practice of Analytical Chemistry

Coming at a much more affordable price is also very encouraging, particularly if you are seeking a quick reference book of principles and techniques for practical applications. Not as comprehensive as other books, it is a concise presentation of up-to-date information regarding modern molecular spectrometry, atomic spectrometry, and separation techniques.

The focus is more practical in comparison to other books, including chapters devoted to automation as well as the role of computers and microprocessors in analytical chemistry. Thermal and radiochemical techniques are also included in this book, reinforcing its value as a reference book for analytical chemists that are already working in the area. 

Closing Up and Final Thoughts

There are different great books to learn analytical chemistry from out there. There are many different options for each taste. Here we presented the best five in our opinion.

However, if you want a safe choice with which you can never go wrong, don’t think twice a go for Harris’ Quantitative Chemical Analysis. The second runner up would be Skoog’s.

No matter which one you choose, always keep in mind that with a good textbook and with a touch of perseverance, you will find yourself mastering analytical chemistry faster than you think.

Finally, I would like to remind you that if you are going through the awesome process of learning chemistry, we have you covered with reviews for the best textbook on the other major subjects of this science: Check them here for organic, inorganic, physical and general chemistry!

As always, please, let us know in the comments if you find any discrepancy, or if you want to suggest an alternative textbook for discussion. (Since we only include here the books that we have available for review ourselves).

The post The Best Analytical Chemistry Textbook appeared first on Chemistry Hall.

Some other students find are more intimidated by organic chemistry. However, most chemistry students are not incredibly fluent in maths, so all those physical chemistry equations can seem a bit overwhelming.

Physical chemistry isn’t the easiest subject to learn; it might frustrate you at times. Very basic and important concepts such as thermodynamics and kinetics are often overlooked in basic chemistry courses. However, if you have the right tools, in this case, the right books, you will have no problem whatsoever studying and passing exams. 

For this review, we will look at some of the best physical chemistry textbooks. For better or worse, it doesn’t seem to be a huge variety to choose from, in contrast with what happens with organic chemistry or general chemistry textbooks. So this comparison review will be quite concise, focused on the three most recommended physical chemistry reference books.

In any case, it does not matter if you are a college professor with a physical chemistry course to teach, or a student who is looking for a solid book to study from, either way, you are covered.

Our Top Pick: Which Book Is the Absolute Best?

After having used all the reviewed books, it didn’t take us long to choose McQuarrie’s Physical Chemistry: A Molecular Approach as the absolute best way to study, learn or teach physical chemistry.

Physical Chemistry: A Molecular Approach

McQuarrie is definitely the king. The red book, even being still on it’s first edition, is undefeated as the best book to learn physical chem. I know many students that had another books defined as course assignment text, but turned to McQuarrie’s to really be able to grasp everything and ace the courses.

McQuarrie’s is just the way to go in most situations, you cannot go wrong with it.

The Best Physical Chemistry Books Reviewed

And now we jump right into the entire reviews!

1. Physical Chemistry: A Molecular Approach

Authored by Donald A. McQuarrie and John D. Simon, this chemistry book is, without a doubt, the most logical and best physical chemistry book you will find anywhere. If you are a beginner, and you plan on getting your feet wet in physical chemistry, this book is an excellent choice.

Physical Chemistry: A Molecular Approach

The book is logically organized, and its concepts are clear and very easy to follow. The math, which is also clear and easy to follow, comes before the physical chemistry chapters. For beginners, I find this helpful because rather than assuming you learned the math elsewhere, the book explains it to you. And there are adequate mathematical reviews at the end of each math section that you can go over. 

For more advanced students or courses, you aren’t left out. This book is the go-to textbook in the area of Thermodynamics and Quantum. I have never seen quantum chemistry explained in any other book as beautifully and enjoyably.

There are many problems on each chapter. You can grab a copy of the problems and solutions manual for McQuarrie here. Many say it is a must if you are interested in focusing on solving problems (which are the main part of courses and exams), or if you are an instructor.

What Makes McQuarrie’s Physical Chemistry the Best?

After explaining the mathematical equations in the math chapters, the book then introduces the fundamentals of quantum theory with explanations. And then base everything else on a microscopic, atomic/molecular standpoint. And this is revolutionary because it helps students to see the subject in a unified and logical fashion, not leaving them confused. As you are probably aware, quantum chemistry and thermodynamics cover many concepts which are difficult to grasp. But not so much with this book. It takes an approach which I feel is the easiest way to learn these concepts.

All in all, I’d say that this book is a must-have physical chemistry textbook that most students of chemistry or college professors and should have on their book shelf. 

I’ve even hear a story of a non-chemist science enthusiast that grabbed a copy of this book and found it to be highly entertaining and instructive! It leaves you with a great feeling on how chemistry works from a (sub)atomic point of view.

To finish, the only drawback is the fact that the book hasn’t been updated since first release, so the figures can be a bit ugly and sometimes not easy to understand.

2. Atkin’s Physical Chemistry

Next runner up is Physical Chemistry by Peter Atkins, Julio de Paula and James Keeler. Now, here’s an updated and nicely illustrated textbook.

It comes in two volumes. The first one covers thermodynamics and kinetics. On my case, I studied quantum at college before thermodynamics and kinetics, so it seemed to me a bit counterintuitive. But I guess the two-volumes distribution was established for exactly this kind of situations.

This is nice, so you only have to buy and handle a 450 pages book for your thermodynamics and kinetics courses.

Atkins’ Physical Chemistry Volume 1: Thermodynamics and Kinetics

The second volume covers quantum chemistry and spectroscopy. It goes on for a little less than 400 pages, and focuses on the physical chemistry itself, not too much in the math behind. it gives just enough to be understandable with a solid base. But you’d better be equipped with that skillset!

Atkins’ Physical Chemistry Volume 2: Quantum Chemistry, Spectroscopy, and Statistical Thermodynamics

Atkins’ books excel in probably being a bit easier to read than McQuarrie’s. It reads pretty much like a novel, and the well illustrated modern figures definitely help. Besides, the book was updated in 2018 with its 11th edition. These are probably the facts that make Atkins’ the most ubiquitous textbook as part university courses syllabus. It’s a great primary resource.

It goes less in depth than McQuarrie’s, but it is arguably easier to read and a bit less dry.

The corresponding Student Solutions Manual also makes Atkin’s text complete.

3. Levine’s Physical Chemistry

I would say that Physical Chemistry by Ira N. Levine is the third most widely used physical chemistry book over the world. This book aims at making the learning process as easy as possible.

Levine’s Physical Chemistry

It comes with stepwise derivations and all maths quite carefully explained. Does a better job than Atkins’ but still not at the level of McQuarrie’s.

This book is on its 6th edition, but this update was released in 2008. It is written on a more formal or more dry manner than Atkins’, but this also makes it pretty specific and concise most of the times.

However, I would not recommend this text over the other two. It does a good job, but Atkins’ and McQuarrie’s do it better.

Closing Up

In summary, whatever textbook you select for guarding you from mighty physical chemistry, be aware that these courses can be a real challenge.

Just put enough time into studying and you will be fine. Also, make sure to have a decent base on maths (especially calculus) before taking physical chem courses. If you put time, have a good base, and one of these great textbooks, you will do fine.

In terms of comparison, we have already stated how McQuarrie’s Physical Chemistry: A Molecular Approach is the winner of the race. It is simply the best book for learning the subject from scratch, since even the math is explained carefully. It is particularly wonderful for quantum mechanics and statistical mechanics.

Even if your course ask you to follow Atkin’s or Levine’s, McQuarrie’s makes up for the best supplement.

On the other hand, Atkins’ can be arguably considered as the best “starting point” book out of the three. That is probably why it is the most recommended one for university courses.

This is all from our side. Make sure to check our general guide for learning chemistry. You can find there plenty of other resources that we have published or updated recently.

And also, please, if you have any comment or suggestion, or another book that you would like to see reviewed, go ahead and hit the comments section!

The post What Is The Best Physical Chemistry Textbook? appeared first on Chemistry Hall.

Here are a couple of fun chemistry experiments that your kids are sure to love.

Chemical Reaction Experiments for Kids: Green Pennies and Copper-Plated Nails

This awesome experiment is really three chemistry experiments for kids in one! First, in Part 1, an acid-base reaction gives dull pennies their original shine back. Then, in Part 2, we use redox chemistry to turn some of those pennies green. Finally, in Part 3, we coat ordinary steel nails in copper.

What you’ll need:

• About 20 dull pennies
• A shallow bowl (glass or plastic only)
• ¼ cup white vinegar
• 1 teaspoon salt
• A couple of clean steel nails
• Water
• Paper towels

Part 1: Making Dull Pennies Look Shiny and New

1. Combine the vinegar and salt in the bowl and stir to dissolve the salt.
2. Start by dipping a penny halfway into the vinegar solution and holding it there for 20 seconds. Make a note of what you see.
3. Dump the remaining pennies into the bowl and leave them there for 5 minutes.
4. Your pennies should be bright and shiny again! Reserve the solution for Part 3.

What’s going on?

Over time, shiny copper pennies get dull because the metal is gradually oxidized when in contact with air. The chemical reaction for this process is 2 Cu (s) + O₂ (g) –> 2 CuO (s). Copper (II) oxide (CuO) or cupric oxide, the product of this reaction, is dull and greenish. So, a layer of this substance on the surface of the penny makes it look dark brown and dull.

Cupric oxide is also soluble in many acids, including the acetic acid in household vinegar. When you place the dull pennies in the vinegar solution, the acetic acid dissolves the cupric oxide on the surface of the pennies, revealing the shiny pure copper metal underneath.

It’s an acid-base reaction that results in invisible copper ions (Cu²⁺) being left in the vinegar solution: CuO (s) + 2 CH₃COOH (aq) –> Cu(CH₃COO)₂ (aq) + H₂O (l). This will be important in Part 3, so don’t throw this solution away!

Part 2: Green Verdigris Pennies

1. Remove the pennies from the vinegar solution. (Keep it for Part 3.)
2. Place half on a paper towel to dry, and rinse the other half thoroughly in clean water before placing them on a separate paper towel. Label the paper towels so you know which is which.
3. Wait about an hour and note the difference between the two sets of pennies.
4. The unrinsed pennies should have turned a blue-green color!

What’s going on?

The turquoise-colored coating on the unrinsed pennies is a patina called verdigris. You might recognize it as being similar to the color of the Statue of Liberty—that’s verdigris, too! While verdigris can be several different compounds, in this fun chemistry experiment, it is copper (II) acetate, or cupric acetate.

It’s a two-step process. First, the copper metal is oxidized to cupric oxide, exactly the same way it does naturally over time. However, in this experiment, we have sped up the oxidation reaction using salt (NaCl) dissolved in the vinegar. Sodium chloride is an electrolyte, and since oxidation-reduction reactions rely on the movement of electrons, an electrolyte acts as a catalyst by increasing the conductivity of the solution.

In the second step, the acetic acid left on the unrinsed pennies reacts with the cupric oxide to form blue-green cupric acetate: CuO (s) + 2CH₃COOH (aq) –> Cu(CH₃COO)₂ (s) + H₂O (l)

Notice that this is the same reaction that dissolved the cupric oxide in Part 1. The difference is that we’ve taken it out of the aqueous environment. Because of this, the solid cupric acetate remains on the penny as the water evaporates.

Part 3: Copper-Plated Nails

1. Place one nail in the solution from Part 1 so that it is half covered, and completely submerge another nail. Note any changes you see.
2. Leave the nails that way for about 10 minutes. If the color hasn’t changed, come back again in an hour.
3. The parts of the nails in contact with the solution should now be coated in copper!

What’s going on?

Steel is an alloy whose main component metal is iron. When you dip the nails in the penny-cleaning solution, the acid in the vinegar dissolves some of the iron and iron oxides on the surface, leaving it with a negative charge.

Remember those invisible Cu²⁺ ions that were left behind in solution? Those positive ions are attracted to the negative charge on the surface of the nail. As a result, the copper ions are reduced (i.e. gain electrons) to pure copper metal, which is deposited all over the nail.

This is definitely one of the coolest chemistry experiments to do at home, and you probably have everything you need already!

More Chemistry for Kids: Coffee Filter Chromatography

This is one of the easiest chemistry experiments with household items, which makes it suitable for even younger kids. It’s an at-home version of something chemists do in the lab every day: chromatography. Here, you will take a dye from markers and separate it into its component pigments.

( As a fun continuation of this experiment, why not use water to pull the dye off of colored candies, like M&Ms and Skittles? Do you think red M&Ms contain the same pigments as red Skittles? How can you find out? )

What you’ll need:

• Coffee filter
• Ruler
• Scissors
• Pencil
• Non-toxic markers (or other source of dye)
• Water
• Table salt
• A tall glass

What to do:

1. Cut the coffee filter into a square, approximately 3 inches by 3 inches, and use a pencil to lightly mark a line straight across the filter, about a half inch from the edge.
2. Next, use the pencil to make dots for each dye color you are going to test, equally spaced along the pencil line, and label each dot with the name of the color.
3. Now, use each marker to make a small dot on the pencil dot by its corresponding label. Ensure that each colored dot is approximately the same size.
4. Prepare a 1% salt solution by dissolving 1/8 tsp table salt in 3 cups of water. Once the salt is dissolved, pour a small amount of solution into the tall glass. The water level should be approximately ¼ inch high. It is very important that it be lower than the marker dots on your coffee filter.
5. Crease the filter square vertically down the middle so that it can stand upright. Then, gently set it in the glass so that the edge below the marker dots is in the salt solution. Water will start to move up the coffee filter.
6. When the water has almost reached the top of the filter square, remove it from the solution and let it dry.
7. The pigments in the markers should have been carried up the filter, some farther than others. What do you see?

What’s Going On?

This chemistry experiment with household items is a simplified form of chromatography, a technique that real scientists use to separate components of a solution every day.

There are two phenomena at work here. First, capillary action is what causes the liquid to defy gravity and move up the coffee filter. This happens in small tubes (like the porous fibers of the coffee filter) when the intermolecular forces between the liquid and the tube are stronger than the force of gravity pulling on the mass of liquid in the tube.

But the second part is what makes chromatography so useful. Some of your marker colors will have moved higher up the coffee filter than others. It’s likely that a few of them even separated into multiple dyes (e.g. a blue spot and a yellow spot came from your green marker). Chromatography uses the different physical and chemical properties of different molecules to separate them in this way.

Sometimes, a dye will move faster up the coffee filter (the “stationary phase”) simply because it is a smaller molecule and weighs less. Usually, though, molecules are separated by their affinity for the stationary phase or the “mobile phase” (the salt solution in our case).

More polar molecules will have a stronger affinity for the positive and negative ions in the salt water, for example, and will be carried up the filter more easily. Nonpolar molecules, on the other hand, will not have any attraction to these charges, and will not get swept away by the solution so quickly.

Your Own All-Natural pH Indicator

Tons of household liquids “behave” the way they do because they are acidic, neutral, or basic. You could check the pH of these liquids with test strips or an indicator solution you buy at a pool supply store or the pet shop. But did you know you can do this with an ordinary vegetable?

The gorgeous colors in this simple experiment make it chemistry for kids at its best!

What you’ll need:

• Half a red cabbage
• 2-3 cups boiling water
• Strainer
• Various household liquids for testing (e.g. plain water, lemon juice, baking soda solution)
• One clear glass for each liquid
• Additional water for diluting

What to do:

1. Prepare the pH indicator from the cabbage. To do this, chop the cabbage into small pieces, cover in a saucepan with boiling water, and let cool. Strain to separate the liquid, which should be dark purple. This is your indicator solution.
2. Dilute a small amount of your household substances in water in separate glasses. Make sure to label them so you know what’s what. It’s a good idea to have one glass of plain water to act as a control.
3. Predict what color each liquid will turn when you add the pH indicator, and then see if you’re right by pouring a small amount into each glass.
4. Neutral liquids should be purple, like the indicator itself. Acidic liquids should turn hot pink, and basic liquids should turn blue!

What’s going on?

Acidity, for the purposes of pH, is a measure of hydrogen ions (H⁺) in a solution. A pH of 7 is considered neutral. If a liquid is acidic, its pH will be between 0 and 7, and if a liquid is basic or alkaline, its pH will be between 7 and 14.

A pH indicator works by reacting with acidic (H⁺) and basic (OH^–) ions in a solution; the product of that reaction is a different color than it was originally, thus indicating whether the solution was basic or acidic.

In red cabbage, the plant pigment anthocyanin has a molecular structure that allows it to act as both a base (reacting with acids) and an acid (reacting with bases). It therefore has three different forms, each with a different color, depending on the number of acidic hydrogens it contains (fully protonated in an acidic environment, partially protonated in a neutral environment, and fully deprotonated in an alkaline environment).

Final Thoughts on Chemistry for Kids

These fun chemistry experiments with household items are simple, safe and visually interesting for kids. But to make sure they get the most out of it, don’t forget to ask them questions (and do your best to answer theirs). What do they see? Why might that be happening? What would happen if you changed the conditions slightly?

You’ll have a budding scientist before you know it!

Also, make sure to check some of the more general science experiments that you can do at home that we have also published recently.

The post Awesome Chemistry Experiments For Kids To Do At Home appeared first on Chemistry Hall.

There is so much to this science that it can be hard to even know where to start! That’s why we put together this guide with recommendations for how to learn chemistry, plus tons of useful resources no matter what your level is.

What exactly is this guide?

Obviously you won’t learn chemistry reading this blog post by itself. This is more of a pedagogical article. However, we will point you towards tons of resources for learning this science, no matter if you are just a chemistry enthusiast or a college student.

This is a general introduction for approaching chemistry, from any level.

There is a very specific way of thinking that helps tackling the problems that chemistry has to offer. We will base our guide upon that cornerstone.

And you will find out what this theme is pretty soon if you keep reading.

An Introduction to Chemistry

But first, a quick introduction to the study of chemistry, what it is, and why you should make the effort to learn this awesome science.

What Is Chemistry?

Chemistry can be defined as the study of matter and the changes it undergoes. You’ll sometimes hear it called the central science because it is the connection between physics and all the other sciences, starting with biology. All that makes it sound abstract and esoteric, but really, chemistry is all around us. It wouldn’t be a stretch to say that it governs every aspect of your life.

Are you sitting inside? You’re surrounded by building materials that are structurally sound because of how chemistry holds them together. Reading this outside? Every living plant you see is consuming CO2 and releasing oxygen in the process of photosynthesis. The food you eat, the products you use to clean your house, the fuel you put in your car, the very air you breathe—it’s all chemistry.

What’s really incredible about chemistry is the seemingly infinite variety of stuff around us and the fact that it’s all just combinations of around 100 chemical elements. In reality, most of what we interact with in everyday life is made up of far fewer. When two or more of these elements are combined in a compound, the properties of the compound can be amazingly unlike the constituent elements. Would you guess that the table salt in your kitchen is made up of a chemical weapon and a metal that causes an explosion when it touches water?

What is Chemistry Used for?

It should come as no surprise, then, that chemistry is used for just about anything you can imagine. Life itself relies on chemistry, but humans have been harnessing it for our own benefit for thousands of years, knowingly or not. From our first combustion reaction (making fire) to the latest cutting-edge medical technology, this science has changed our lives in ways that are mind-blowing.

Long before we knew any scientific concepts that we take for granted today, we were performing basic chemistry. Some of the most important examples from the ancient world are processes that we still use today, such metallurgy and extracting compounds from natural sources, e.g. plants.

Many people consider alchemy to be the forerunner of modern chemistry. This is debatable, but regardless, the discipline that tirelessly sought a way to turn lead into gold fell out of favor among intellectuals right about the time when something closer to modern chemistry was beginning to catch on. The earliest publications in chemistry as a proper science date to the 16^th and early 17^th centuries.

Now, a few hundred years later, the field has positively exploded, with numerous subdisciplines. Today, we say that the five major branches of chemistry are general chemistry, organic chemistry, inorganic chemistry, biochemistry, and analytical chemistry. But there are tons of more niche areas of chemistry, too, like physical, materials, and nuclear chemistry, neurochemistry, chemical engineering, medicinal chemistry and pharmacology… The list goes on and on because chemistry is used for everything!

Why Should I Learn Chemistry?

So, aside from the fact that it is used for practically everything in life, why should you learn chemistry? There are tons of reasons!

Even if you don’t plan on a career in science, you’ll pick up a lot of useful skills and knowledge when you learn chemistry. Studying science helps you understand important issues, like climate change or food additives, more objectively. Chemistry is also great for developing problem solving skills.

More specifically, knowledge of chemistry unlocks some of life’s most profound mysteries… like how to make sure your baked goods come out moist and fluffy! Seriously though, it can make many routine tasks—like cooking—easier, and more importantly, it can help keep you safe. Knowing which cleaning products are okay to be used together and which should never be mixed is possible with chemistry, as is understanding how certain medicines work in your body, and much more.

This video sums it up really well:

Besides, chemistry is not a profession which seems to be going anywhere soon. Careers and jobs in chemistry, especially in research, are usually pretty fun, and creativity-driven.

Now that you’re convinced that you want to learn chemistry, how do you do it?

How to Learn Chemistry

I talked with many people that have studied chemistry, like myself, and everyone seems to have learnt this science very similarly.

There is a way of reasoning and thinking about chemistry which is common in chemical education.

Chemistry is an empirical science, so it is based on explaining observations, and taking what you extract from those observations to extrapolate and make predictions about other phenomena.

You can explain extremely simple chemistry questions, such as differentiating organic and inorganic compounds, to very complex scenarios with this same methodology.

This way of reasoning is, in my opinion, the best way to tackle chemistry problems. This goes from a kid learning basic science to a professional chemistry PhD working on ground-breaking research.

How to Rationalize, Explain and Extrapolate

To illustrate this, we will use a simple example:

First an observation: We observe that water freezes at a certain temperature (0 ºC at atmospheric pressure).

Then, rationalization/explanation: Thanks to previous knowledge, we can explain this observation in simple terms saying that at lower temperatures, molecules vibrate less, and can pack in a more efficient manner. The way water molecules can pack below 0 ºC, gives it a solid state structure.

We can generalize this to any other substance: Depending on how strong are intermolecular interactions between each molecule of a given substance, they will be able to pack in a solid state form more easily (at higher temperature).

Then we extrapolate to other systems/molecules: intermolecular forces between hexane molecules are much weaker (dispersion forces) than between water molecules (hydrogen bond). This will make it harder to pack them in a solid state structure, thus making its melting point much lower (-95 ºC, to be exact).

And this turns out to be true, as we can easily validate by determining (or consulting) the melting point of hexane.

And this can be made as simple as that or as complex as you would like your model to be.

This way of thinking fits perfectly with chemistry. That’s why I highly recommend it.

If you already took chemistry courses, you are probably familiar with this reasoning process, even if you didn’t really notice.

Where to Find Any Resource for Learning Chemistry

So you are already packed with a clear thinking process that you can adopt for tackling chemistry.

What do you need now?

Of course, you need information. Information is everything. You need books, resources and materials to study.

Well, we have good news for you! We live in the age of information technologies, and you can find literally everything anywhere. You can order a textbook from almost anywhere, and even find electronic versions of those books. You can find scientific research articles from home. You can visit Wikipedia and take a quick look about any subject you want. You can Google whatever you want and find tons of resources to learn from…

One might say, that there’s too much information out there! More than you can handle!

But I really don’t think there’s such a thing as ‘too much information’. Not if you are good at searching through it, and filtering what’s important. And this is a basic yet overlooked skill in our age. Focus on learning how to process, select and filter! And this not only applies to chemistry, but to every subject out there.

To be completely honest, even in 2020, I don’t think there is a better way to learn a natural science such as chemistry than starting from a good textbook.

Not get me wrong, there is plenty of info about chemistry. Heck, probably most of the university level course materials can be found in Google.

However, there is nothing like the great and didactical organization of a textbook. You can get one for your level, and when you are done going through most of it, you will be a master on that level. Of course, I encourage you to expand every topic that is not clear enough, or not covered deeply enough. For this purpose, or for a quick outlook, the internet is amazing.

There are plenty of different textbooks for any level. Which one is the best for me? What are my options? This is what we will cover next.

We strongly recommend you to navigate this site through the links on each section to check specific details and thorough comparison data.

The Best Books to Learn Chemistry at Any Level

No matter what your interest or level in this subject may be, there’s a great book out there to help you learn chemistry. This section won’t be too extensive, but you can find detailed write-ups on all of the books below in other posts.

Kids and Casual Learners

Our recent post on the best chemistry-themed gifts included three books that are a great fit for older kids or adults who have a casual interest in the central science.

Elements: A Visual Exploration of Every Known Atom in the Universe is visually stunning and chock full of cool information. It contains gorgeous photos and fun facts, and it would be an excellent introduction for people who are curious to learn about the chemical elements that make up our universe.

Ask a Science Teacher: 250 Answers to Questions You’ve Always Had About How Everyday Stuff Really Works is a book that is less focused on chemistry specifically, but which has still got tons of fascinating explanations in plain English. It’s a great book to show all the practical ways in which science affects us every day.

Chemistry for Everyone: A Helpful Primer for High School or College Chemistry is exactly what it sounds like. It’s definitely the most educational of the books in this section, although it is not intended to replace a complete chemistry course. We would recommend picking this up before taking your first chem class so that you have an idea of what to expect.

High School

We have two favorites when it comes to books for high school chemistry students. You can read more in our post on these and other high school chem textbooks, but here are our top picks in a nutshell:

Chemistry: Concepts and Problems: A Self-Teaching Guide is, of course designed for self-taught students. This makes it ideal if you end up in a class with a “teacher who doesn’t teach”, as students often report. It’s based on the programmed learning method for maximum learning effectiveness.

Chemistry for Dummies tracks a typical introductory chemistry course, making it suitable for high school and college intro to chem classes. No matter what your current level is, you can learn chemistry with this book.

We also published a separate review for the best chemistry books for self-study, which can be suitable for anyone, but especially to people at the high-school level.

University Level

At the university level, there are several types of chemistry courses you could be taking, each with its own separate textbook. Or, if you’re curious to learn chemistry but don’t need the credit to graduate, you could use one of these books to teach yourself!

If you’re learning General Chemistry, we’ve got a whole post dedicated to the best books for this class. But in the interest of time, our two top picks are Brown’s Chemistry: The Central Science and Tro’s Chemistry: A Molecular Approach. Both are top-notch textbooks, with the second one being a bit more expensive but also more accessible for most students, especially visual learners.

For people with a serious interest in learning chemistry, the next course is usually Organic Chemistry, or o-chem. Your professor has likely listed a book on their syllabus, but in our opinion, the best textbook to learn organic chemistry is Clayden’s Organic Chemistry. According to research, students value clarity above all else in textbooks, and this one is very easy to follow with plenty of practice problems. We also try to publish resources in which reaction mechanisms are well explained, here is an example with the Swern oxidation!

Your o-chem professor will probably also require or suggest you get a molecular modeling kit. This is highly recommended, even if it isn’t mandatory in your class. But remember, it doesn’t do any good to buy a kit if you don’t use it, so make sure you take full advantage of all the concepts it can help you understand.

By the time you get to Inorganic Chemistry, you’ve likely made a major commitment to studying chemistry. There are several inorganic chemistry textbooks that can help you learn more effectively, but our preference is Housecroft & Sharpe’s Inorganic Chemistry. It’s got just the right balance of detail and being easy to understand with very instructive graphics.

Two other main fields of chemistry are not forgotten. Here you can go and check for the best physical chemistry textbooks and the best analytical chemistry books.

Other important subfields such as biochemistry and electrochemistry are not left behind.

Also, it is mandatory that you start learning how to properly take notes in the form of a laboratory notebook, and writing good lab reports.

Online Resources

Apart from books, the second best resource for finding resources is clearly the internet. But what sites should I visit?

Of course, there are many university websites with plenty of information, but the easiest and quickest way find something, is of course, a search engine such as Google. But make sure to check what kind of site are you visiting, and if the information they provide is reliable. Many times, your query will take you to university sites that you can trust. But as we advised before, learning how to filter information is key!

As for other great websites to look for information, some of them are:

Wikipedia: Some criticize that anyone can edit it and write any information. This is true, but it is also true that it undergoes continuos review by experts, and inaccurate or undocumented information rarely goes unnoticed. The info sources or citations are usually great and often refer to original research.

Youtube: Just the same as Google, just search anything you want and you will most likely find a channel explaining everything about it to you! An example for Organic Chemistry is presented by Crash Course here.

As an example of this, we have collected some of the best chemistry lectures and conference talks in another article.

SciFinder and Reaxys: Professional scientific databases. They are paid tools, but if you study or work in a research institution, you will most likely have access to a subscription. These are great for looking through original research, and if you are serious about doing a career on chemistry, you’d better get used to playing with them!

Libretexts: Great repository for completely open access books online, which might not be accessible anywhere else. Lot’s of chemistry material there to find!

This list could go on forever, for example, our own place, Chemistry Hall, has plenty of resources to discover. But we really want to remark how important is to master search engine searches to look for exactly what you are looking for.

We will now finish with an important section for students: tips on taking on some of the most popular standarized chemistry exams in the US.

Taking Standardized Chemistry Exams

The single best thing you can do to prepare for most standardized exams is to take practice tests that are as similar to the real thing as possible. In addition to that, check out these tips for some of the major standardized chemistry exams.

Tips for AP Chemistry Exams

The AP chem exam is a college credit exam for high school students, so it literally pays to be prepared for this one. Your first step should be to buy one of the best AP chemistry review books, preferably one with lots of practice test so that you’ll feel comfortable with the structure of the exam and the formats of the different types of questions.

When taking your practice exams, make sure you do it under simulated testing conditions. Most of all, that means that you need to time yourself. Another important thing to keep in mind is that the topics that are covered on the exam are changed from time to time, so if you buy a review book, make sure it’s the most recent edition.

Similarly, make sure you get the latest version of exam logistics, such as when you will be allowed to use a calculator, the provided equation sheet, etc. And if your handwriting looks like chicken scratch, remember that your free response questions are being graded by humans, and doing your best to keep things legible could save you some points by making your grader’s life easier.

Tips for the SAT Chemistry Subject Test

Many colleges and universities do not require SAT II exams, i.e. subject tests, but they can be useful to present yourself as a better applicant. Usually, students are advised to take one science SAT subject exam and one humanities, and the SAT Chemistry Exam is one of the most popular science tests.

It should come as no surprise that your first step to success is to buy a chemistry SAT subject textbook. But it’s also important to realize that not all review books are created equal. There is one specific type of question on the SAT Chemistry Exam that is quite different from what most students are used to. They are called “relationship analysis”, and they can be confusing at first, so you need to make sure that your practice exams contain this type of problem.

When taking practice tests, always do it as close to real-life testing conditions as possible. That means setting a timer and being aware in advance of the things that are and aren’t allowed on exam day. For example, you are NOT permitted a calculator on the chemistry SAT II. If your algebra and basic math skills aren’t strong, it’s best to start working on them as far in advance of exam day as you can.

You will, however, be given a very basic periodic table of the elements. It wouldn’t be a bad idea to review periodic trends, groups, series, etc. and make a “brain dump” of all this information as soon as you are allowed to begin the test.

Tips for ACS Exams

Some college professors opt to give the American Chemical Society general chemistry or organic chemistry exam as their course final in lieu of preparing their own. This sounds like a terrifying prospect to lots of students, but it can actually be a blessing because you will be able to prepare yourself for it with more confidence.

Since the ACS exam is standardized, you can know in advance exactly what topics will be covered, the sorts of questions they tend to ask, etc. You can find official study guides and practice tests online, along with the rules for the test, provided materials, and so on.

We recommend that you start prepping well in advance so that you can space out the material and take your time with everything. Remember that active forms of studying, like doing practice problems or trying to explain concepts to someone else, are much more effective than just reading and rereading notes.

The ACS finals are cumulative, which means they are more about breadth than depth in terms of material. You can choose to go back to the beginning of your course work and study chronologically, or take a more tailored approach and first focus on material that you have a good, but not great, understanding of, before continuing on to any parts that make you feel hopelessly lost.

Tips for MCAT, PCAT, etc.

Pre-professional exams, like the MCAT and PCAT, are designed to measure your knowledge and aptitude in multiple subjects. On the MCAT, one section is called Chemical and Physical Foundations of Biological Systems, while the comparable section on the PCAT is Chemical Processes (there is a separate section for biology).

The names of these sections give you a clue as to what you are expected to know on each exam. Understandably, there is a greater focus on chemistry in this section for pharmacy students and more of a biology focus for med school.

The two exams have totally different structures and rules, so you need to get all that information as soon as you can so that you know how to study and prepare. For example, the PCAT is now given on the computer at a testing center with a calculator built into the exam in the chemistry section and others. However, calculators are not allowed on the MCAT chemistry section, so part of your test prep may include practicing doing calculations by hand.

As with other exams, you’ll greatly improve your chances of getting into med school or pharmacy school if you make use of a good review book with plenty of practice problems.

Time to Learn Chemistry!

If you follow this guide and make use of the resources at your disposal, you’ll be well on your way to learning chemistry. Now, all you need is to dedicate some time to daily study—consistency will make the difference in how far you go!

The post How To Learn Chemistry at Any Level appeared first on Chemistry Hall.

We have reviewed and updated this guide recently, so it is ready for 2020. You can check the best available options right now.

Get ready to share a great adventure into chemistry together with your kids!

Why Do Chemistry Experiments at Home?

Kids are naturally curious about the world around them. Satisfying and encouraging that curiosity will help lay the foundation for a lifelong love of learning.

Chemistry is driving practically everything that happens in the universe, and the best way to learn it is to see it in action. Think back to your own schooldays. What parts of science class were the most memorable? The experiments and demonstrations!

Chemistry is an empirical or experimental science, and it is extremely difficult to make it enjoyable for a kid using only theory, or textbook explanation. Many chemists even admit to not like chemistry very much when they were kids! This was because their learning experience lacked of experiments.

Basically, the reason to find the best chemistry set for kids with age-appropriate experiments is that they are educational and totally cool. Students of all levels can learn important science concepts and have tons of fun doing it.

We have previously covered how to set up a home chemistry lab, but today we focus on another very important topic: learning together with our kids!

And this kind of sets go beyond learning chemistry. If you are interested in other fields of science, you should go and get your hands into a science kit.

If you are looking for something to give as a gift to a chemist, check out this gift review!

In this post, we’ve got our pick for the best chemistry set for kids, as well as detailed reviews for eight different chemistry kit products, all ideal for classroom or home use.

Our Top Choice for Best Overall Chemistry Kit

As always, we start this review post with our number one pick. Today, that designation goes to the Thames & Kosmos Chem C2000 kit. This would be considered the intermediate chemistry set, between the C1000 and the C3000 products.

Thames & Kosmos Chem C2000 (V 2.0)

We rate this best overall because of the amazing number of projects, quality materials and full-color experiment manual. It is on the higher end of the price range among the kits in this article, but with everything you get, it is a great value.

Chem C2000 was the best in 2019, and is still the best option out there in 2020.

The Chem C2000 chemistry set includes around 250 experiments with professional quality equipment. As such, it is ideal for homeschooling and traditional classrooms alike.

Thames & Kosmos recommend this kit for ages 11 and up; after all, there are some pretty serious chemicals in here, not to mention an alcohol burner for experiments that require heat.

Quick Comparison Table

The Best Chemistry Sets for Kids

Now, starting with our top pick, we’ve got detailed reviews of eight products which provide fun chemistry experiments for kids of all ages.

1. Thames & Kosmos Chem C2000

Thames & Kosmos offer a range of Chem kids’ science kits, and the C2000 falls right in the middle in terms of extensiveness, level, and price. It comes with the equipment and supplies you need for some 250 experiments with a comprehensive lab manual to guide budding scientists through each activity.

Thames & Kosmos Chem C2000

We would rate this as the ideal beginner chemistry set for older elementary school and up. Thames & Kosmos are famous for their award-winning products, so it’s no wonder they rolled out the best science kit for kids. Both this and the more basic C1000 kit have won awards from the Parents’ Choice Foundation.

Although it does not have as many experiments as the C3000 kit, it is very complete and very professional. It is recommended for ages 11 and up, but honestly, adults are just as likely to find this chemistry kit enjoyable and educational as children are.

Of particular note in the C2000 set is the alcohol burner, which greatly expands the number of possible experiments by providing a heat source.

2. Thames & Kosmos Chem C3000

This product is, of course, the more advanced premium option from Thames & Kosmos. Compared to the C2000 model, this chemistry kit has about 333 experiments, with extremely high quality equipment.

Thames & Kosmos Chem C3000

If you don’t mind the higher price point, this would definitely be the best chemistry set for adults of all the products on this list. It is just about the closest thing you’ll find to a professional chemistry set out there.

The C3000 model is recommended for ages 12 and up, and its experiments cover some fairly advanced topics. It would make a great companion to high school science, and would be right at home in the classroom as well.

If you are looking for a more advanced chemistry set for teenagers, this is probably a very nice bet.

3. Thames & Kosmos Chem C1000

Once again, another product from Thames & Kosmos that ranks among the best science kits for kids. Unlike its higher-end counterparts, the C1000 has just 125 experiments. However, this is still a very complete set, recommended for ages 10 and up.

Thames & Kosmos Chem C1000

Perhaps the most obvious benefit of the C1000 chemistry set compared to the other to is its more affordable price. Considering everything you get, we would still call the C2000 a better overall value, but this is another excellent choice.

Also, the Parents’ Choice Foundation has dubbed this one of the best chemistry sets for kids, too, by giving it their gold award.

4. Ben Franklin Toys Chemistry Lab Pad Science Kit

This product from Ben Franklin Toys is one of several options for chemistry kits for kids in preschool and early elementary school. Accordingly, it puts a focus on safety and exploration, and it is designed for children ages 5 and older.

Ben Franklin Toys Chemistry Lab Pad Science Kit

The distinguishing feature of the Lab Pad Science Kit is, you guessed it, the lab pad. Parents and preschool teachers will appreciate the lab pad, because it serves as both a work surface for experiments and storage for all the included equipment. As a result, everything stays nice and organized in between science days.

However, the experiments in this product are very limited. In contrast to the other chemistry sets on this list—even the ones designed for younger kids—it only has around 12 activities to do. The price for this product is in the middle of the range, but if you are looking for a great variety of experiments to do with your kids, then it might not be the best value.

5. Learn & Climb Kids Science Kit

Another chemistry set for kids designed for the preschool and kindergarten age group, the Learn & Climb Fun with Science kit is suitable for ages 5 and up.

Learn & Climb Kids Science Kit

Unlike the previous product, Learn & Climb provides a much more complete kit. It contains over 60 experiments, compared to just 12 in the Ben Franklin Toys product, and it retails for a lower price.

In fact, we would rate this as the best chemistry set for kids between the ages of 5 and 10. The number and variety of activities is quite impressive, it is very affordable, and it is designed to help kids learn and explore independently. On this last point, the kit includes a kid-friendly experiment manual and an instructional DVD to guide young scientists through each project.

6. Learning Resources Primary Science Deluxe Lab Set

If the Learn & Climb science kit is the best option for elementary school-aged children, then this lab set from Learning Resources is the best chemistry set for kids who are still in preschool. Designed for children as young as 3 years old, it is perfect for the youngest scientists.

Learning Resources Primary Science Deluxe Lab Set

This kit comes with 20 double-sided activity cards that guide students through experiments with step by step instructions. Altogether, it’s a great kit for giving kids their first exposure to real scientific equipment, like test tubes, flasks, funnels, and even a “science view scope” that looks like a microscope.

So, if you want to encourage scientific exploration in your children or students between the ages of 3 and 5, then this would be our top recommendation.

7. Dan & Darci Light Up Crystal Growing Kit

One of the most rewarding and visually impressive science experiments you can do with your kids is crystal growing. While natural crystals take thousands of years to form in the ground, crystal growing kits like this one from Dan & Darci take just one week or less to form beautiful crystals that will fascinate children and adults alike.

Light-up Crystal Growing Kit for Kids

Although the kit is not recommended for use by kids under 8 years old, your younger kids can still get excited checking the crystals each day to see how much they’ve grown.

The Dan & Darci crystal growing kit is very reasonably priced for this type of product. It comes with materials to grow three crystals: one red, one blue, and one colorless. All you have to do is add boiling water and follow the instructions.

Arguably the most standout feature of this specific crystal growing kit is the LED light display. Once your crystals have finished growing, simply use the included USB charging cable to charge the LED display, and then set your crystals on top and enjoy the beautiful results.

8. Happy Atoms Magnetic Molecular Modeling Complete Set

When kids start learning about atoms and molecules in middle and high school, the new information can be very abstract and overwhelming. Don’t let this discourage them! Instead, help them feel curious and confident by putting those molecules right in their hands.

Happy Atoms Magnetic Molecular Modeling Complete Set

This Happy Atoms kit might seem somewhat expensive for a molecular modeling kit; however, it has a very innovative special feature that accounts for the more premium price. In addition to the magnetic atoms and bonds, it comes with a scanning mat and a free app download that will scan and identify the molecules your child builds.

Because of this, it is a great tool for kids aged 10-17 as they go through their first dedicated chemistry classes. Also, it comes with 216 enrichment activities that are fun and sure to foster a love of science.

If you want more info on molecular modeling kits, make sure to check our previous review.

FAQ (Frequently Asked Questions)

In all cases, any time you are performing chemistry experiments, always make sure that you wear lab safety glasses. Protect your eyes (and your kid’s) at all costs.

Choosing the Best Chemistry Set for Kids

Luckily, this is a very easy choice for parents and teachers to make. After all, the main factor to consider is the age of the children who will be using the kit.

If your young scientist is at least 10 years old, then one of the Thames & Kosmos chemistry sets will be most appropriate for general chemistry experiments, especially the Thames & Kosmos Chem C2000 model. This is a great option that even adults will enjoy. The chemistry kits from this series are a great complement for learning chemistry in high school too.

If they are taking chemistry in high school, teenagers would also strongly benefit from the Happy Atoms molecular modeling kit and its companion mobile app.

For elementary-aged kids, approximately ages 5-10, we would recommend the Learn & Climb Kids Science Kit. This is because of its excellent array of experiments compared to similar products, its great value, and its clear focus on kids.

Finally, the Learning Resources Primary Science Deluxe Lab Set is certainly the best chemistry set for kids who are still in preschool and too young for the Learn & Climb kit. With visual instructions, bright colors, and safe experiments, it’s ideal for ages 3+.

If you want to check out some chemistry experiments that you can do at home without having to purchase any kit, make sure to check these examples.

So you see, there are great options available to do fun chemistry at home no matter where you kids are on their learning journey. These experiments are so cool, they won’t even realize they’re educational!

The post The Best Chemistry Set for Kids (and Adults!) appeared first on Chemistry Hall.

Even more complicated was the situation for students studying chemistry. This is because chemistry is not only a tough subject, but it requires utter concept traction as well. 

Thanks to advances in technology, all this has now changed. Today, it is easier for a student to find online tools that offer chemistry lessons. Whether you need chemistry homework help or simply looking for an avenue to learn, you can get all that on the internet. 

Perhaps the best thing about e-learning is that it is more flexible. This way, you are able to balance your schedule well to meet all your daily demands, without compromising on your chemistry studies. 

While online learning has numerous benefits, there are different emerging challenges that students face on a daily basis. As expected, since the online learning bubble busted, a number of resources were made available.

This is a good thing for students. However, with a tremendous amount of resources available, it can be difficult to understand how to use them. 

So how can you use these resources to improve your understanding of chemistry? This article will guide you on what to do in a bid to use the online resources effectively. Hopefully, they will go a long way in ensuring that you improve in your chemistry class. 

Treat Online Resources Like Real Classroom Resources

The first step to using online resources to your advantage is to, first of all, identify and treat these resources as real classroom resources. Although they may not fully act like physical resources such as books and pamphlets, it’s important to know that they offer equal, if not more, information on chemistry lessons. 

Whether you are using these resources for free or paying for them, always remember to follow through with your dedication to using them as though they were your textbooks or library resources. 

Additionally, if the classes are offered on live streams, ensure to follow through with the classes by strictly adhering to the set schedule. Remember that once you miss an online class, you will have difficulty catching up with the lost class, just like in the physical setting.

Many examples of chemistry courses available online, for different levels, can be found in this reddit post.

Hold Yourself Accountable

As mentioned before, online resources, just like physical learning, come with a lot of challenges. Perhaps using these resources offer an even bigger challenge in terms of concentration.

To successfully use online resources to better understand your chemistry lessons, you should first ensure to hold yourself accountable for everything. This includes identifying what your syllabus is set to cover throughout the semester and working hard to complete all the set units. 

If you find it difficult to ensure that you are accountable, try pairing up with one or two classmates. This way, they will help you take into account what needs to be done at each and every step of your learning process. 

Manage Your Time Well

Regardless of whether you are studying online or physically in a school, possessing impeccable time management skills play an integral role in your overall success. 

While the flexibility to develop a schedule that fits you is one of the most alluring factors to consider when studying online, you should always remember that the freedom that comes with it can be detrimental to your success. 

Without a solid time management system in place, you will not only find yourself with a lot to cover days before the exam, but you will not have time to fully grasp every chemistry concept. 

Make Sure to Stay Organized

Another important element to using online resources to better understand your chemistry classes is to ensure you stay organized. This means organizing all your resources in a manner that makes it easier for you to not only access but use it as well. 

The first step to getting organized is to ensure that you dedicate a specific learning environment. The reason for dedicating a specific study environment is that you will be able to develop a study routine. 

This way, you can achieve a steady routine and be able to better grasp your chemistry concepts with ease. 

Participate Actively

Since chemistry can be quite difficult to understand, it’s of utmost importance to ensure that you actively participate in all your online courses. 

Whether lessons are offered on a live stream or posted on a website, you should ensure to find a way to engage both your teachers and fellow students as well. This way, you will stand a better chance of grasping all the concepts with ease. 

Eliminate Any Distractions

Apart from different forms of online distractions, you can always expect a host of different distractions while using online resources to improve in your chemistry class. 

In order to use these resources effectively, it’s paramount to ensure that you limit any distractions while studying. However, the kind of distractions you will experience while using online resources will solely depend on your own preference and personality.

On one hand, a student would prefer to remove any form of distractions, in the form of noise, by playing music. On the other hand, another student will prefer to study in a completely silent environment.

Regardless of the place or environment, you prefer to study in, there are common things that you should do to mitigate any form of distractions.

One of the things you should always ensure to do is to switch off your phone. This way, you will avoid any forms of distractions in the form of text messages and incoming calls. 

Break Down Tasks

As mentioned before, studying chemistry can be tough. So, how do you deal with such a subject that requires an in-depth understanding? 

The best way is to break down different tasks that have to do with the subject. Consider using other online resources to help you identify and break down the different tasks that you have to accomplish.

This way, you will not only be organized, but you will grasp all the concepts in your chemistry class. 

The post How to Use Online Resources for Learnig Chemistry appeared first on Chemistry Hall.

Nothing can beat a nice molecular model kit for leaning 3D visualization of molecules. In this guide you will learn how to use it, and for what it can be helpful.

If you don’t have one yet, check out our molecular model kit buying guide and find the best one for you!

Molecular Geometry and Covalent Bonding

Molecular models are usually used in organic chemistry classes, but their utility is not limited to o-chem. Some important general chemistry concepts that can be better understood with a model are molecular geometry and covalent bonding.

A cool example is using it to identify stereoisomers of inorganic or organometallic metal complexes:

Most standard kits come with a variety of atoms with different numbers of shareable valence electrons, which are represented as holes. VSEPR theory assumes that the geometry around each atom depends on those valence electrons repelling each other. Because of this, you can get hands-on experience with many different geometric configurations using a molecular model kit.

Unlike ionic bonds, which are formed by the donation and acceptance of electrons, covalent bonds are the result of electrons being shared between two atoms in a molecule. The sharing is not necessarily 50/50, but even so, the bond pieces used in model kits are a good visual and tactile reminder of that shared electron pair.

In any case, these are great for grasping some very important basic concepts in chemistry.

Organic Nomenclature: Build it with Your Molecular Model!

While not normally necessary, model kits can help you with some intentionally tricky organic nomenclature questions that sometimes show up on exams.

You might know that your first step in naming an organic molecule is to find the longest uninterrupted carbon chain. Where they try to trick you on exams is drawing the structure out in a way that makes the longest chain counterintuitive.

Practicing with models can help you learn to look for the longest chain where you might not necessarily expect to find it in the drawing. Physically holding the molecule in your hand allows you to look at it from every angle so that you don’t get tricked.

Alkanes, Alkenes and Alkynes

In organic chemistry, molecular model kits are very useful for understanding some of the properties of double and triple bonds. However, they do have important limitations here, and you need to be aware of them as you learn chemistry.

If you take a look at a carbon atom in your kit (usually black), you’ll see that it has four holes where you can attach bonds, representing carbon’s four valence electrons. When carbon is bonded to four things via single bonds, each of those bonds is a hybrid of s– and p-orbitals; in this case, since all four bonds are equivalent, they must each have sp³ hybridization (one part s and three parts p, divided into four equal bonds), and we call these sigma bonds. (Pop quiz: what geometry is this? What are the bond angles?)

As soon as you make double bonds, things begin to change. The model kit comes with longer flexible bonds that are meant to be used to form double and triple bonds. Looking at a model of, say, 2-butene, it is immediately clear that there are no longer four equivalent bonds on carbons 2 and 3; you had to use different pieces to even represent those bonds on your model.

What might not be clear from the double bonds is that the flexible bond is actually a representation of the pi bond that is left.

Hybridized Orbitals, Sigma and Pi Bonds

Carbon is now bonded to three things, one of which is attached via a double bond. Just like we used one part s and three parts p to create four sp³ orbitals before, we now will take one part s and two parts p to make three sp² hybridized orbitals (again, take note of the geometry and bond angles). These three all form sigma bonds. What about that leftover p? That is the second long, flexible piece in your double bond—it is a purely p orbital, and the bond it forms is called a pi bond.

The same goes for a triple bond: carbon is bonded to two things, so you take one part s and one part p to make two sp hybridized orbitals (sigma bonds), and your two leftover p orbitals each form a pi bond. Thus, a carbon-carbon triple bond is made up of one sigma bond and two pi bonds.

Now, pick up your model of any alkane you like, and notice how all of its bonds have free rotation. Next, make a model of the corresponding alkene or alkyne, and try to rotate about the double or triple bond. You can’t, right? There is no rotating about that bond now without first breaking a bond. This is a very important concept to grasp in organic chemistry, and it is one that molecular models illustrate beautifully.

The drawback to visualizing single, double and triple bonds with some model kit is that the lengths of the bonds may not be to scale. The Molymod one of the pictures comes fairly close to reality, in the sense that triple bonds look shorter than double bonds, but it is not always the case.

You’ll just have to remember that, even though it might look like there is more space between atoms in your double bond, this is just the way the pieces are made. In reality, single bonds are the longest (154 pm), followed by double bonds (134 pm) and then triple bonds (120 pm).

Visualizing Chirality and Stereochemistry with a Molecular Model

Chirality is one of the trickiest concepts for first-semester organic chemistry students, and a molecular model kit can really make it “click”.

On paper, it can be hard to see the difference between, say, (R)-1-chloroethanol and (S)-1-chloroethanol. But as soon as you build the two models—nonsuperimposable mirror images of each other—you will see that, just like your right hand and your left hand, they are not the same.

Determining the R/S configuration around chiral carbons is almost always easier when you can hold a physical model and turn it over in your hands. No matter how the molecule is presented to you on paper (dashes and wedges, sawhorse, Fisher projection, Newman projection, etc.), a molecular model lets you see it in 3D and orient it correctly.

However, being able to rotate different projections and determine R/S configuration without a tactile aid may be necessary if a molecular model kit is not allowed on any exam you might take. In this case, definitely practice doing it completely on paper, but take advantage of the model as a tool to help bridge the gap in spatial reasoning if you find this challenging.

Another fabulous use for molecular models on this topic is demonstrating how a molecular can have chiral carbons and still not be a chiral molecule.

For example, use your kit right now to build cis-1,2-dichlorocyclohexane, confirm that it does indeed have two chiral centers, and then build its mirror image. You will see that the mirror image is superimposable, and therefore, the molecule is not chiral.

Go ahead and try the same but with trans-1,2-dichlorocyclohexane. What happens on this case? Is that molecule chiral or not? Hint: look for mirror planes.

Steric Hindrance and Reactivity

The last topic we’ll cover in this post on how to learn chemistry using a molecular model kit is steric hindrance. This is a key concept in understanding organic reactions because it will help you see whether a given nucleophile or electrophile is accessible enough to participate in the reaction.

To see this, all you need to do is build a primary, a secondary and a tertiary substrate. In our case, we will show you the difference in reactivity through nucleophilic substitution reaction of two chlorophosphines.

You know that an atom bond to a good leaving group such as a halide (chloride) is an electrophile and, in theory, vulnerable to nucleophilic attack. But do you see how much “stuff” would get in the way of your nucleophile if it tried to attack an electrophilic center with a tert-butyl group? That is steric hindrance, and it can make the difference between a straightforward reaction and one that is a total nonstarter.

You can clearly see how the presence of a bulky group really hinders the approach of an external nucleophile (too much repulsion!) and blocks the reactivity, sometimes slowing down the reaction, and sometimes shooting it down completely.

If you are interested, I recommend you to take a look to our previous post on steric effects in organic reactions to learn more.

Apart from reaction rates. using your molecular model kit to illustrate the steps in substitution and elimination reactions is also helpful in predicting the stereochemistry of the products.

Choosing the Best Molecular Model Kit

Those are just some of the many ways a molecular model kit can help you learn chemistry, especially organic chemistry. Real molecules exist in three dimensions, and you will get a better understanding of what’s really going on with them when you can hold them in your hand, manipulate them, and look at them from every angle. The pictures from this guide were made using a Molymod molecular kit, since it was the only one I had around when I prepared the post.

However, if you want to make sure you buy the best molecular model kit, we highly recommend Dalton Lab Kit.

It’s middle of the road in terms of price, but with 306 pieces it is an excellent value. Plus, it comes with access to the manufacturer’s online 3D molecular modelling software. You also get the peace of mind of a money back guarantee.

Dalton Labs Molecular Model Kit

But if you decide to buy a different kit, no worries!

We have an entire review about choosing the best molecular modeling kit to fit all your needs: Check our complete review here!

They are very affordable and worth every penny—a molecular modelling kit is one of the best investments you can make in your chemistry education.

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