Chemistry is one of the most mesmerizing (and sometimes dangerous) sciences. While some chemical reactions are parts of our daily lives — such as mixing sugar with coffee — others are more complex and require controlled conditions to visualize the effects. This is especially true for situations where the reaction could result in fire, dangerous fumes, an explosion, or showers of sparks.
The safest way to experience these types of reactions is to watch from afar — such as through your computer screen. Below are 18 striking videos that will ignite your passion for chemical reactions.
1. Diethylzinc and Air
Diethylzinc is a very unstable compound. It will react violently and ignite when it comes into contact with water, air, and just about anything that can either accept a pair of electrons or donate a proton. It is shipped in sealed tubes with carbon dioxide and can be used as an aircraft fuel. In this video, when it comes in contact with oxygen, it burns to form zinc oxide, CO2, and water.
2. Cesium and Water
Cesium is one of the most reactive alkali metals. When it comes into contact with water, it reacts to form cesium hydroxide and hydrogen gas. This reaction occurs so rapidly that a hydrogen bubble forms around the cesium, rises to the surface, which then exposes the cesium to the water causing further exothermic reaction thus igniting the hydrogen gas. This cycle repeats until all of the cesium is exhausted.
Cesium is most commonly used as a drilling fluid. It is also useful in making special optical glass, radiation monitoring equipment, and in atomic clocks.
3. Calcium Gluconate and Heat
Calcium gluconate is typically used to treat calcium deficiencies. However, when it is heated, the calcium gluconate breaks down and oxidizes, forming water vapor and carbon dioxide. The products of breakdown, calcium oxide and carbon, have a greater volume than the initial substance, and so a "snake" forms.
4. Nitrogen Triiodide and Touch
You can make this inorganic compound at home, but be aware that it is very dangerous. The compound is formed through the careful reaction of iodine and ammonia, by reacting iodine with an aqueous ammonia solution. The result is an extremely sensitive contact explosive. Small amounts will explode with a loud, sharp snap when touched even lightly with a feather, releasing a purple cloud of iodine vapor.
5. Ammonium Dichromate and Heat
At room temperature, ammonium dichromate – also known as "Vesuvian Fire" – exists as orange crystals. When it's ignited, it decomposes exothermically, producing sparks, steam, and nitrogen gas, like a mini volcanic eruption. It also produces green chromium (lll) oxide "ash." Ammonium dichromate has been used in pyrotechnics, photography, and lithography. It can also be used as a mordant for dyeing pigments.
6. Hydrogen Peroxide and Potassium Iodide
When hydrogen peroxide and potassium iodide are mixed in proper proportions, the hydrogen peroxide decomposes very quickly. Soap is often added to this reaction to create a foamy substance, sometimes called "elephant toothpaste" as a result.
The soapy water traps the oxygen, a product of the reaction, and this creates many bubbles. While hydrogen peroxide is often used as a disinfectant, potassium iodide can be used as a medication — it is used to treat hyperthyroidism.
7. Potassium Chlorate and Sugar
Gummy bears are essentially just sucrose and potassium chlorate is used in explosives, fireworks, and matches. However, when gummy bears are dropped into potassium chlorate, and a drop of sulfuric acid added as a catalyst, the two chemicals react violently with each other, releasing large quantities of heat energy, a spectacular purplish flame, and a great deal of smoke in a highly exothermic combustion reaction.
8. Belousov-Zhabotinsky (BZ) Reaction
The BZ reaction is a family of oscillating chemical reactions formed by the combination of bromine and an acid. The reaction is a prime example of non-equilibrium thermodynamics and results in the colorful chemical oscillations you see in this video.
9. Nitrogen Monoxide and Carbon Disulfide
Often referred to as the "barking dog" reaction, this is a chemical reaction that results from the ignition of carbon disulfide and nitrogen monoxide, or nitrous oxide, in a long tube. The reaction produces a bright blue flash and a barking or woofing sound.
When the mixture is ignited, a combustion wave travels down the tube. The gas ahead of the wavefront is compressed and explodes at a distance that depends on the length of the tube. The exothermic decomposition reaction between nitrogen monoxide (oxidizer) and carbon disulfide (fuel) forms nitrogen, carbon monoxide, carbon dioxide, sulfur dioxide, and sulfur.
In April 1853, Justus von Liebig, who is considered one of the principal founders of modern organic chemistry, performed the barking dog reaction in front of the Bavarian royal family. Unfortunately, the glass container shattered, injuring the family and Liebig himself.
10. NaK Alloy and Water
NaK alloy is a metal alloy formed by the mixing of sodium and potassium in the absence of air – usually under kerosene. This extremely reactive alloy will react with air, but an even more violent reaction occurs when it comes in contact with water. The heat given off by this reaction rapidly melts the sodium and potassium and is often enough to ignite the hydrogen gas produced.
While the reaction may seem straightforward, scientists are still puzzled over exactly why the process occurs so quickly.
11. Thermite and Ice
Ever thought that mixing fire and ice together could result in a boom?
This is what happens when you get a little help from thermite, which is a mixture of aluminum powder and the oxide of a metal, such as iron. When this mixture is ignited, there’s an exothermic oxidation-reduction reaction, i.e. a chemical reaction in which electrons are transferred between the two substances. The reaction produces large amounts of heat as flame and sparks, and a stream of molten iron and aluminum oxide.
When the thermite is placed on top of ice and ignited with the help of a flame, the ice is immediately set on fire and a large amount of heat is released in the form of an explosion. There isn’t a scientific consensus on why thermite causes an explosion when combined with ice. But one thing is pretty clear from the demonstration video — do not try this at home!
12. Briggs-Rauscher Oscillating Clock
Briggs-Rauscher reaction is one of a very few oscillating chemical reactions. The three solutions required for this observation are a diluted mixture of Sulfuric Acid (H2SO4) and Potassium Iodate (KIO3), a diluted mixture of Malonic Acid (HOOOCCH2COOH), Manganese Sulfate Monohydrate (MnSO4. H2O) and vitex starch, and lastly, diluted Hydrogen Peroxide (H2O2).
The reaction produces visually stunning effects as the color of the solution changes back and forth. To initiate the reaction, the three colorless solutions are mixed together. The resulting solution will cycle while changing color from clear to amber to deep blue repeatedly for 3 to 5 minutes before ending up as a dark blue color.
13. Supercooling Water
In this experiment, purified water is cooled below its freezing point and then crystallized into ice with a single tap. This can be done at home with a bottle of distilled water. Simply allow it to chill in the freezer, undisturbed, for about two hours. Then take it out and give it a shake or tap.
Since the water has no impurities, water molecules have no nucleus around which to form solid crystals. The external energy provided in the form of a tap will cause the supercool water molecules to form solid crystals through nucleation and will start a chain reaction that rapidly crystallizes the water throughout the entire bottle.
14. Ferrofluid and Magnetic Fields
Ferrofluid is composed of nanoscale ferromagnetic particles suspended in a carrier fluid such as organic solvent or oil. The magnetic particles are also coated with a surfactant to prevent clumping. They were originally discovered by the NASA Research Center in the 1960s, as a part of an investigation to find methods to control fluids in space.
When exposed to strong magnetic fields, ferrofluids will produce spectacular shapes and patterns. These fluids can be prepared by combining proportions of Fe(II) salt and Fe(III) salts in a basic solution to form Fe3O4.
15. The Giant Dry Ice Bubble
If you can find some dry ice (frozen carbon dioxide), try this experiment to produce a giant bubble at home — make sure to take proper precautions with the dry ice though!
Take a bowl and fill it halfway with water. Squirt liquid soap in water and stir it. Make the edges of the bowl wet using your fingers and add dry ice to the solution. Dip a circular strip of cloth in soapy water and pull it across the entire rim of the bowl. Wait for a moment as the dry ice gas becomes trapped inside the soap bubble, which will begin to expand gradually as the CO2 gas expands.
16. Mercury Thiocyanate and Heat
When mercury (II) thiocyanate is ignited, it results in a rapid exothermic reaction that produces a growing snake-like column and colorful flames, an effect also known as The Pharaoh’s Snake. Mercury thiocyanate was formerly used in fireworks. All mercury compounds are toxic, and the safest way to perform this experiment is in a fume hood.
17. The Meissner Effect
Cooling a superconductor below its transitional temperature will make it diamagnetic — causing it to float above a magnet. This effect has led to the concept of frictionless transportation, where an object can be levitated along a track rather than attached to the wheels. This effect, however, can also be easily replicated in a lab. You’ll need a superconductor and a neodymium magnet, along with liquid nitrogen. Cool the superconductor with liquid nitrogen and place the magnet on top to observe the levitation.
18. Superfluid Helium
A superfluid is a state of matter in which matter behaves like a fluid with zero viscosity. The point at which a fluid transitions to a superfluid is called the lambda point. Cooling helium to its lambda point (-271° C) will make it a superfluid is known as Helium II.
Helium's ability to remain liquid at very low temperatures allows it to form a Bose-Einstein condensate, and individual particles overlap until they behave like one big particle. In this frictionless state, the helium will do things that other fluids can't, like move through molecule-thin cracks, defy gravity by climbing up the sides of a dish, and remain motionless inside a moving container.