In acidic solution the iodate ion can be used to react with

In acidic solution, the iodate ion can be used to react with a number of metal ions. One such reaction is:
IO3- (aq) + Sn^2+ (aq) ---> I- (aq) + Sn^4+ (aq)

Since this reaction takes place in acidic solution, H2O (l) and H+ (aq) will be involved in the reaction. Places for these species are indicated by the blanks in the following restatement of the equation:
IO3- (aq) + Sn^2+ (aq) + ___ ---> I- (aq) + Sn^4+ (aq) + ___

What are the coefficients of the six species in the balanced equation above? Remember to include H2O (l) and H+ (aq) in the appropriate blanks.

Solution

IO3(-)+6e+6H(+)=I(-)+3H2O
Sn(2+)=Sn(4+)+ 2e- !!x3

------------------------------------------

IO3- (aq) + 3Sn^2+ (aq) + 6H+ ---> I- (aq) + 3Sn^4+ (aq) + 3H2O