5 K2S-II + 8 KClVO3 + 4 H2SVIO4 9 K2SVIO4 + 4 Cl20 + 4 H2O

This is an oxidation-reduction (redox) reaction:

5 S-II - 40 e- 5 SVI (oxidation)

8 ClV + 40 e- 8 Cl0 (reduction)

Change the oxidation states