C3-IIH8O + 6 I20 + NaOH HCIIOONa + 2 CIIHI3-I + 6 HI-I

This is an oxidation-reduction (redox) reaction:

3 C-II - 12 e- 3 CII (oxidation)

12 I0 + 12 e- 12 I-I (reduction)

Change the oxidation states