SO32- --> SO42-
S = 4+ S = 6+
0 = 2- -----> O = 2-
There is a change of 2+ charge from left side to right side
so I would want to add 2e- to lower the charge on the right side correct??
You are mixing two things - half reaction method and ON method. When balancing by half reaction, don't look at ON, just balance atoms and charge as listed.
http://www.chembuddy.com/?left=balancing-stoichiometry&right=half-reactions-methodYour equation is at this moment already balanced with regard to charge - there is -2 on both sides, you don't have to do anything with that. Oxygen is not balanced, as there there is more oxygen on the right than on the left. Thus you have to balance oxygen with water and H
+ - and once this is done balance charge:
H2O + SO32- --> SO42- + H+ + 2e-
Wrong, but good as a starting point. Remove all electrons. Balance hydrogen. Calculate total charge of molecules (don't touch ON, only charges are shown - +1 for H
+ and -2 for both SO
x2-) on both sides - and than add electrons to balance it. For obvious reasons you will have to add on the right number of electrons identical to number of H
+ cations.