During electrolysis, where do positive ions collect?

• A. At the anode
• B. At the cathode
• C. In the electrolyte near the anode
• D. In the solid electrode

Answer: (B)

Positive ions accumulate at the cathode, the negative electrode, because that’s where electrons are supplied from the power source. When they reach the cathode, they gain electrons (are reduced) to become neutral atoms or molecules. For example, in molten salt electrolysis, Na+ moves to the cathode and becomes Na metal, while Cl− moves to the anode and forms Cl2 gas.