Question

balance equation by electron balancing method
cl2 + oh- = cl- + clO3- + h2O

Answer 1

You really do need to find the caps key on your keyboard and learn to use it.
Cl2 + OH^- = Cl^- + ClO3^- + H2O
Separate into two half equations.
Cl2 ==>Cl^- and Cl2 ==> ClO3^-
Balance each separately.
Cl2 + 2e--> 2Cl^- for the first one, then
Cl2 ==> 2ClO3^-. Cl2 has oxidations state of 0 and on the right it is +10 so
Cl2 --> 2ClO3^- + 10e. Now balance the charge with OH^-.
Cl2 + 12 OH^- ==> 2ClO3^- + 10e. Now balance the H.
Cl2 + 12 OH^- ==> 2ClO3^- + 10e + 6H2O for the second one.

Now multiply the first one by 5, the second one by 1, add them and the equation will balance BUT then you can divide everything by 2 and that will be the final equation you want. Post your work if you get stuck.

Answer 2

Cl2 ==> 2ClO3^-. Cl2 has oxidations state of 0 and on the right it is +10 so
Cl2 --> 2ClO3^- + 10e. Now balance the charge with OH^-.
How +10????