I−+(IO3)−+5+H−→I20+H2O2I−I2+2e− ?(i) x 5 10e−+2(IO3)−1+5I20 ?(ii) On adding Eqs. (i) and (ii), we get 10I−+2IO3−6I2 To balance O atom, add 6H2O molecules/on RHS and 12H+ on LHS, then 10I−+2IO3−+12H+6I2+6H2O or 5I−+IO3−+6H+3I2+3H2O