Balance the following equations given that they occur in alkaline solutions.

a) ClO^-_(aq) + CrO₂^-_(aq) => Cl^-_(aq) + CrO₄^-2_(aq)

3ClO^-_(aq) + 2OH^-_(aq) + 2CrO₂^- => 3Cl^-_(aq) ++ 2CrO₄^-2_(aq)+ H₂O_(l)

b) Al_(s) + NO₃^-_(aq) => Al(OH)₄^-_(aq) + NH_3(aq)

8Al_(s) + 3NO₃^-_(aq) + 5OH^-_(aq) + 18H₂O_(l) => 8Al(OH)₄^-_(aq) + 3NH_3(aq)

c) Cr(OH)_3(aq) + IO₃^-_(aq) => CrO₄^-2_(aq) + I^-_(aq)

4OH^-_(aq)+ 2Cr(OH)_3(aq) + IO₃^-_(aq) => 2CrO₄^-2_(aq) + I^-_(aq)+ 5H₂O_(l)