Question

Use the half reaction method to balance each redox reaction occurring in acidic aqueous solution S2O3 2-(aq) +Cl2(g)= SO4 2-(aq)+Cl-(aq)

Answer 1

The final balanced equation is: 10H2O + 2S2O3 2- + Cl2 -> 4SO4 2- + 20H+ + 2Cl- .

Balancing the Redox Reaction using the Half-Reaction Method:

Step 1: Identify Oxidation and Reduction:

S2O3 2- is oxidized to SO4 2-.

Oxidation half-reaction: S2O3 2- -> SO4 2- + 8e-

Cl2 is reduced to Cl-.

Reduction half-reaction: Cl2 + 2e- -> 2Cl-

Step 2: Balance the charges in each half-reaction:

Oxidation half-reaction: 5H2O + S2O3 2- -> 2SO4 2- + 10H+ + 8e- (add 8 H+ to balance O and 10H+ to balance charge)

Reduction half-reaction: Cl2 + 2e- -> 2Cl-

Step 3: Balance the number of electrons transferred:

Multiply the oxidation half-reaction by 2:

10H2O + 2S2O3 2- -> 4SO4 2- + 20H+ + 16e-

The number of electrons transferred in both half-reactions must be equal.

Therefore, the final balanced equation is:

10H2O + 2S2O3 2- + Cl2 -> 4SO4 2- + 20H+ + 2Cl-