Chemistry can be a challenge for many schools with safety considerations and equipment availability. At the same time, students learn best by doing and take a lot away from physical experimentation and replicating reactions they have learnt in theory. Video is a great compromise so that students can see how amazing chemistry can be without putting themselves at risk or breaking the bank.
Here are a collection of the 7 impressive reactions that should motivate your class to understand the science behind the spectacle:
1. Briggs–Rauscher reaction
The Briggs–Rauscher oscillating reaction is one of a small number of known oscillating chemical reactions. It is especially well suited for demonstration purposes because of its visually striking colour changes. The detailed mechanism of this reaction is quite complex but the effect is beautifully hypnotic.
2. Pharaoh’s Serpent
From the beauty of the Briggs–Rauscher reaction, the pharaoh’s serpent looks like something from a horror movie. The reaction is caused by the heating of Mercury Thiocyanate where a rapid exothermic reaction produces a large mass of coiling serpent-like solid.
3. Elephant Toothpaste
Elephant toothpaste is a foamy substance caused by the rapid decomposition of hydrogen peroxide. This is often used for classroom demonstrations because it requires only a small amount of ingredients and makes a “volcano of foam”.
4. Thermite and Liquid Nitrogen
Thermite is a pyrotechnic composition of a metal powder and a metal oxide that produces an exothermic oxidation-reduction reaction known as a thermite reaction. Braniac puts a competitive swing on the reaction pitching it against liquid nitrogen.
Ferrofluids are colloidal liquids made of nanoscale ferromagnetic, or ferrimagnetic, particles suspended in a carrier fluid (usually an organic solvent or water). When exposed to strong magnetic fields the fluid produces amazing shapes and patterns.
6. Potassium Chlorate and Gummy Bear
Potassium Chlorate is a compound containing potassium, chlorine and oxygen. When potassium chlorate is heated to melting point, any item added to it will cause a rapid disintegration in the form of an explosion. The sugar from the Gummy Bear burning produces the glittering spark reaction seen in the tube.
7. Dry Ice Bubble
One of the safer experiments to reproduce, this reaction is more for fun than science. As suggested this experiment can be a good one with Halloween approaching.
Image courtesy of Flickr, [F]oxymoron