Write a balanced chemical equation describing the oxidation of Cl2 gas by Cu3 + to form chlorate ion (ClO3-) and Cu2 + in an acidic aqueous solution. Use the smallest whole-number coefficients possible and indicate states of matter in your balanced reaction.

Cl2 (g) + 10 Cu3 + (aq) + 6H2O (l) → 2 ClO3 (aq) + 10 Cu2 + (aq) + 12 H + (aq)

Explanation:

Step 1: The half reactions

Cl2 (g) + 6H20 (l) ⇆ 2ClO3 - (aq) + 12H + (aq) + 10e-

Cu3 + (aq) + e - ⇆ Cu2 + (aq)

Step 2: Balance the reactions

To balance the electron transfers, we have to multiply the second equation by 10

Cl2 (g) + 6H20 (l) ⇆ 2ClO3 - (aq) + 12H + (aq) + 10e-

10 Cu3 + (aq) + 10e - ⇆ 10 Cu2 + (aq)

Step 3: The netto reaction

Cl2 (g) + 10 Cu3 + (aq) + 6H2O (l) → 2 ClO3 (aq) + 10 Cu2 + (aq) + 12 H + (aq)