Which condition is required to drive electrolysis of water?

• A. Increased temperature
• B. Direct current electricity
• C. A strong catalyst
• D. High atmospheric pressure

Answer: (B)

Direct current electricity is needed because water electrolysis is not spontaneous; it requires external energy to drive the non-spontaneous redox reactions that split water into hydrogen and oxygen. A steady, unidirectional flow of electrons from a power source pushes reduction at the cathode (producing hydrogen) and oxidation at the anode (producing oxygen). If alternating current were used, the electrode roles would continuously swap each half cycle, canceling the overall reaction and preventing sustained gas production. Other factors like higher temperature, catalysts, or pressure can influence how fast the reaction proceeds, but they do not provide the essential energy input that a direct current source supplies.