Chemistry HW help

Question

Complete and balance the following redox reaction in basic solution. Be sure to include the proper phases for all species within the reaction. IO3-(aq) + S2-(aq) --> IO-(aq) + SO2(g)

Answer 1

IO₃^-(aq) ==> IO^-(aq) .. unbalanced reduction reaction

IO₃^-(aq) ==> IO^-(aq) + 2H₂O(l) .. balanced for I and O

IO₃^-(aq) + 4H₂O(l) ==> IO^-(aq) + 2H₂O(l) + 4OH^-(aq) .. balanced for I, O and H (using base)

IO₃^-(aq) + 4H₂O(l) + 4e- ==> IO^-(aq) + 2H₂O(l) + 4OH^-(aq) .. balanced reduction reaction

S^2-(aq) ==> SO₂(g) .. unbalanced oxidation reaction

S^2-(aq) + 2H₂O(l) ==> SO₂(g) .. balanced for S and O

S^2-(aq) + 2H₂O(l) + 4OH^-(aq) ==> SO₂(g) + 4H₂O(l) .. balanced for S, O and H (using base)

S^2-(aq) + 2H₂O(l) + 4OH^-(aq) ==> SO₂(g) + 4H₂O(l) + 6e- .. balanced oxidation reaction

Multiply reduction rxn by 3 and oxidation rxn by 2 to equalize electrons, then add together and combine/cancel like terms:

3IO₃^-(aq) + 12H₂O(l) + 2S^2-(aq) + 4H₂O(l) + 8OH^-(aq) ==> 3IO^-(aq) + 6H₂O(l) + 12OH^-(aq) + 2SO₂(g) + 8H₂O(l)

3IO₃^-(aq) + 2H₂O(l) + 2S^2-(aq) ==> 3IO^-(aq) + 2SO₂(g) + 4OH^-(aq) .. balanced redox equation

Answer 2

If you are simply looking for the answer (and not the process to get it), here's the answer:

IO₃^-_(aq) + S^2-_(aq) + H₂O_(l) → IO^-_(aq) + SO_2(g) + 2 OH^-_(aq)