Question

What does this chemical reaction describe? water → hydrogen + oxygen respiration decomposition of water combustion of hydrogen fuel chemical reaction in a battery

Answer 1

I think it describes a chemical reaction in a battery involving the decomposition of water into hydrogen plus oxygen gas by electrolysis due to an electric current passing through the water and causing the dissociation of the two constituent elements. This is why water in wet cell battery can be seen to be bubbling during this process. Wet cell batteries must have water to function properly. and the water must be filled up regularly as it gets consumed.