Oquizy

What is the oxidation state of sulfur in H₂SO₄?

+2 +4 +6 -2

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

Which of the following is reduced?

Cu → Cu²⁺ Fe³⁺ → Fe²⁺ O²⁻ → O Zn → Zn²⁺

What is oxidation in terms of electron transfer?

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

An aqueous solution of sodium chloride is electrolysed using carbon electrodes. When the solution is dilute, gas X forms at the anode. When it is concentrated, gas Y is released instead.What are gases X and Y?

X: Cl₂, Y: O₂ X: H₂, Y: Cl₂ X: O₂, Y: Cl₂ X: O₂, Y: H₂

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