How to make a chemical heating pad
Using a chemical reaction to get warm
Just a small heating pad to warm your hands this winter!
Perform this experiment only under adult supervision.
- resealable bag;
- mineral filler;
- zinc powder;
- copper sulfate;
Put some zinc powder, copper sulfate, and mineral filler in a resealable bag. Mix thoroughly and add some water with a syringe. Your heating pad is activated!
Zinc is a rather reactive metal, and readily forces less reactive metals from their salts. The copper sulfate, and the copper in its composition, is one such example. Adding water initiates a reaction in which zinc replaces the copper ions in the sulfate, yielding a copper precipitate. This reaction also releases heat, and as the zinc is powdered, the reaction proceeds quickly enough to generate a large amount of heat in a short time.
A similar experiment is included in the “Thermal effects” kit from the MEL Chemistry subscription.