Question

Balance the following redox reaction occurring in an acidic solution:
ClO4^-+Br2=Cl^-+BrO3^-

I get the two half reactions balanced as:
6e^-+(8H^+)+ClO4^-=Cl^-+4H2O

and

6H2O+Br2=2BrO3^-+(12H^+)+10e^-

Then I multiply the top equation by 5 and the bottom equation by 3. The e^- would equal 30.

When I add them together though, the charges don't balance once the e^- are canceled out. What am i doing wrong? I hope you can read the equations.

Answer 1

The first half equation is not balanced. Cl on the left is 7+ and on the right is 1- so delta e is 8e on the left. You will notice the charges don't balance in your half equation. 1+ on the left and 1- on the right.

Answer 2

Thanks! I should have noticed that.