Oquizy

John tries electroplating. He uses a copper spoon as the cathode, and a pure copper rod as the anode in copper(II) sulfate solution. After 30 minutes, the mass of the spoon increases by 2.4 g. What happens at the anode?

Anode dissolves completely Mass decreases by 2.4 g Mass increases by 2.4 g No change in mass

In the electrolysis of aqueous copper(II) sulfate with carbon electrodes, which are the products?

Cu at both electrodes Cu at cathode, H₂ at anode Cu at cathode, O₂ at anode H₂ at cathode, O₂ at anode

What is oxidation in terms of electron transfer?

Gain of electrons Gain of protons Loss of electrons Loss of neutrons

What is the correct half-equation at the anode?

H⁺ + e⁻ → ½H₂ H₂ → 2H⁺ + 2e⁻ H₂O → ½O₂ + 2H⁺ + 2e⁻ O₂ + 4e⁻ → 2O²⁻

In the electrolysis of molten sodium chloride, what is formed at the cathode?

Chlorine gas Hydrogen gas Sodium ions Sodium metal

Which ionic half-equation shows oxidation?

2H⁺ + 2e⁻ → H₂ Cl₂ + 2e⁻ → 2Cl⁻ Cu²⁺ + 2e⁻ → Cu Zn → Zn²⁺ + 2e⁻

Quiz: Chemistry - Redox Chemistry