In electrolysis of water, why is the volume of gas collected over one electrode double that of gas collected over the other electrode?
In the electrolysis of water, the gas collected at cathode is hydrogen and the gas collected at anode is oxygen. The gas which is collected in double amount is hydrogen. This is because water contains two molecules as compared to one molecule of oxygen.
The reaction that takes place in the formation of water from H2 and O2 is:
2H2 + O2→ 2H2O