Electrode Products in Electrolysis

Steps:

• In electrolysis, cations move to the cathode (negative electrode) and are reduced; anions move to the anode (positive electrode) and are oxidized.
• For molten lead bromide (PbBr₂), the ions are Pb²⁺ and Br⁻, with no water present.
• At the anode, 2Br⁻ → Br₂ + 2e⁻, producing bromine gas.
• Verify other options against standard electrolysis rules for aqueous or molten electrolytes.

Why A is correct:

• Anions (Br⁻) are oxidized at the anode to form Br₂, as per the half-equation 2Br⁻ → Br₂ + 2e⁻ in molten salts without competing species.

Why the others are wrong:

• B: Positive ions (cations) are discharged at the cathode (negative electrode), not the anode.
• C: In aqueous NaCl, H₂O is reduced at the cathode to form H₂, not Na, due to water's lower reduction potential.
• D: Dilute H₂SO₄ electrolysis produces O₂ at the anode and H₂ at the cathode from water; SO₂ is not formed.

Final answer: A