In electrolysis, which electrode is the negative electrode?

• A. Cathode
• B. Anode
• C. Electrolyte
• D. Inert electrode

Answer: (A)

In electrolysis, the electrode connected to the negative terminal of the power supply becomes the negative electrode, the cathode. Electrons are pushed into the cathode, so cations in the electrolyte move toward it and gain electrons (reduction). The opposite electrode, connected to the positive terminal, is the anode, where oxidation occurs. The electrolyte is the liquid or solution that contains the ions, and an inert electrode is a conductor that doesn’t participate in the chemical reaction. For a quick example, in molten sodium chloride, Na+ ions move to the cathode and gain electrons to form Na metal, while Cl− ions move to the anode and lose electrons to form Cl2 gas.