When electricity is passed through water, it undergoes a chemical decomposition reaction called electrolysis. This process splits water (H2O) into its component gases: hydrogen (H2) and oxygen (O2). At the cathode (negative electrode), hydrogen gas is produced, and at the anode (positive electrode), oxygen gas is released. This reaction can be represented as: 2H2O(l)→2H2(g)+O2(g)2H_2O(l)\rightarrow 2H_2(g)+O_2(g)2H2​O(l)→2H2​(g)+O2​(g) The volume of hydrogen gas produced is twice that of oxygen gas because each water molecule contains two hydrogen atoms and one oxygen atom. Electrolysis is the chemical effect of electric current on water, resulting in the breaking down of water molecules into simpler substances.