On the small scale, they’re just atoms interacting, swapping bonds, and producing energy. On the large scale, some chemical reactions are interesting, dramatic, or possibly even violent. Assembled here are 10 of the coolest chemical reactions packaged up as handy GIFs. Check out the gallery above for each GIF, then read the descriptions below to learn what makes each one do that crazy thing.
1. Aluminum and bromine
Some chemical reactions proceed along at a leisurely pace and don’t produce a lot of excess energy. Then there are those like the reaction of aluminum and bromine as seen in the first GIF. Bromine is extremely volatile by itself but aluminum reacts violently with all halogen elements, including bromine. This GIF shows the conversion of aluminum bromate salts and some flaming bits of elemental aluminum thrown off by the strongly exothermic reaction.
2. Explosive polymerization of p-Nitroaniline
This GIF shows what happens when you mix a chemical known as p-Nitroaniline with a strong sulfuric acid. The acid decomposes the molecule, but also produces gases like sulfur dioxide, water vapor, and carbon dioxide. This process happens extremely quickly polymerizes to form a column of flame retardant material known as a pyrostat. NASA has investigated this reaction as a fire suppression system.
3. Tin decomposition
This is technically more of a physical reaction in response to temperature, but it’s close enough. GIF number three shows what happens when pure elemental tin is left in cold temperatures. Often called tin pest, tin slowly undergoes an autocatalytic transformation at temperatures below 13.2 degrees Celsius. It moves from the metallic beta form we associate with tin, to a brittle alpha form that crumbles due to its diamond structure.
4. Nitrogen triiodide
What is this? Harry Potter-style wizardry? No, that’s just what happens when you disturb nitrogen triiodide. This compound is a type of extremely sensitive contact explosive. It consists of one nitrogen atom and three iodine atoms. The instability is a result of the strain caused by three very large iodine atoms latched onto the same central nitrogen. The slightest tap can break the bonds and release all that pent up energy as nitrogen gas.
5. Mercury reacting with aluminum
Aluminum usually has a protective oxide layer, but if that is scratched or sheared off, it becomes vulnerable to decomposition by mercury. The mercury atoms pull aluminum atoms out of the perfectly ordered matrix, but these atoms quickly recombine with oxygen in the air to form that aluminum oxide layer again. However, it’s formed in the wrong place, which is why all those weird metallic growths are spreading across the surface in the GIF. The substance of the aluminum structure is slowly torn apart and falls to the ground in a few hours.
6. Strontium, sulfur, and heat
The test tube in this GIF contains strontium sulfate (that’s strontium and sulfur) and carbon. When heated to over 1000 celsius, an energetic reduction kicks in that produces carbon dioxide and strontium sulfide. It basically loses the oxygen atoms that were in the starting material. As a neat bonus, the reaction looks like hellish, glowing brimstone.
7. Giant gummy bear in potassium chlorate
Potassium chlorate is nasty stuff. Not only is is explosive and irritating to skin, it’s a very strong oxidizer. That means it strips electrons off other atoms and produces heat in the process. The sugar in gummy candy contains a lot of energy, and oxidizing it rapidly results in what you see in the above GIF. It’s basically instant fire.
8. Trimethylaluminium and air
Trimethylaluminium is dangerous stuff, but not because it’s particularly toxic. This molecule contains aluminum and three methyl groups, which makes it useful for various industrial applications. The problem, however, is that its carbon-aluminum bonds are very weak. Aluminum forms very strong bonds with oxygen from the air, though. The instant trimethylaluminium hits the air, it combusts as bonds break and the aluminum is oxidized. It’s like liquid fire.
9. Sodium polyacrylate with water
Sodium polyacrylate is the chemical compound used to create artificial snow, which is what you see in the GIF. It’s sometimes called waterlock for its ability to absorb 200-300 times its mass in water. The super-absorbent properties of sodium polyacrylate also make it useful in the creation of polymers and detergents.
10. Precision iodine clock
We’ve posted about the iodine clock reaction before — it’s one of the most famous reactions in chemistry. It’s a little complicated, but the gist is that iodine atoms in the solution are reacting with starch to produce incredibly strong colors. The concentration of the reactants determines how long the reaction takes to start, which is how these beakers are triggered at precise times.
1. Aluminum and bromine
Aluminum and bromine, strongly exothermic.
2. Paranitroaniline in sulfuric acid
Paranitroaniline in sulfuric acid and an explosive polymerization.
3. Tin decmoposing
Sometimes called tin pest.
4. Nitrogen triiodide
5. Mercury and aluminum
Don’t scratch your aluminum.
6. Strontium, sulfur, And heat
Looks awesome when it reached ignition.
7 gummy potassium chlorate
Don’t play with trimethylaluminium at home.
9. Sodium polyacrylate mixed with water
10. Iodine clock
This takes very careful mixing.