What is an example of a reaction that produces gas (see description)?

For the reaction example, please do not include any hazardous or toxic products or reactants (i.e. H2SO4, HCl, etc.). Also, none of the reactants can be gases. Any help is seriously appreciated and I am quite desperate here! Thank you so much!

1 Answer

Hydrogen peroxide

Explanation:

Hydrogen peroxide (H2O2) is commonly used as a first aid antiseptic and decomposes naturally. They are usually kept in special containers to retain it's chemical properties, but if you poured some into a bowl you would see little gas bubbles rising up.

2H2O2 → 2H2O + O2

hydrogen peroxide → water + oxygen gas