“Nitrocellulose–cellulose’s combustible sibling” experiment
How to make cotton wool burn in a few seconds
In this interesting and dangerous experiment, we will reveal another secret of magicians – how do they set fire to cotton wool in their hands without getting burnt?
Wear protective gloves, a mask and glasses, and work in a well-ventilated room. Observe safety rules when working with concentrated acids, fire and flammable substances.
Warning! Don’t try to repeat this experiment at home. This experiment is supposed to be conducted only by a professional.
Reagents and equipment:
- cotton wool;
- concentrated nitric acid;
- concentrated sulfuric acid;
- concentrated solution of sodium bicarbonate;
- two glass bowls.
Put ice in the first glass bowl, and place a beaker in which we put the cotton wool, then pour sulfuric and nitric acids in the ratio of 2:1. Wait 30 minutes. Then move the nitrocellulose that has formed to the second glass bowl, which is filled with the solution of sodium bicarbonate, to neutralize the remains of the acid. Wring out the nitrocellulose and leave to dry for about half an hour. Light it.
Cotton wool mainly consists of cellulose, a natural polymer from which a very interesting substance can be obtained – nitrocellulose, which is a complex ether of cellulose and nitric acid. For example, it is used to make ping pong balls, and is found in explosive mixtures, smokeless gunpowder, and is used by magicians as a swift-burning component. It was also used in the past as a mount for camera and cinema film, but because of its flammability it was replaced by safer materials.
It burns up so quickly that it doesn’t burn the hand, but non-professionals should still not attempt this experiment:
(C₆H₁₀O₅)n + HNO₃ + H₂SO₄ = [C₆H₇(NO₂)₃O₅]n + H₂SO₄ + nH₂O
Sulfuric acid acts as a dehydrating agent and catalyst of this reaction.