balancing equations

I need help balancing the following for the charge. Eqn: IO3- + I- + H+ ---> I3- + H20 I sometimes get confused when charges are involved so any quick tips would be much appreciated!

Okay so I got this question on my practice exam and there is a conversion factor that I do not understand or better I don't know where they got it from if someone knows please explain consider the unbalanced reaction Na2CO3 +HCl--> CO2 + H2O + NaCl for this reaction, how many ml of a 2M...