Oquizy

Which ionic half-equation shows oxidation?

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

Xinyi filled a beaker with aqueous CuSO₄ for electrolysis and she used inert carbon electrodes. She labels the cathode A and the anode B.
- She observed the following: Bubbles forming at electrode B.
- Red-brown solid forming on electrode A.
Which option correctly identifies the reactions at the electrodes?

A: 2H⁺ + 2e⁻ → H₂; B: Cl⁻ → Cl₂ + e⁻ A: Cu → Cu²⁺ + 2e⁻; B: 4OH⁻ → O₂ + 2H₂O + 4e⁻ A: Cu²⁺ + 2e⁻ → Cu; B: 4OH⁻ → O₂ + 2H₂O + 4e⁻ A: Cu²⁺ → Cu + 2e⁻; B: 2OH⁻ + 2e⁻ → H₂O

An aqueous solution of potassium nitrate is electrolysed using inert platinum electrodes. What are the products at the electrodes?

Hydrogen and nitrogen Hydrogen and oxygen Potassium and nitrogen Potassium and oxygen

What happens to the mass of the cathode during copper electroplating?

Decreases Increases Stays the same Turns green

What is oxidation in terms of electron transfer?

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

Why is hydrogen gas not always produced at the cathode during electrolysis of aqueous solution?

Hydrogen ions are neutral Hydrogen is heavier than water It depends on the concentration and reactivity Water evaporates quickly

Quiz: Chemistry - Redox Chemistry