C6H10O5 + H2O2 + 2 KI + H2SO4 → C6H10O5I2 + K2SO4 + 2 H2O
This is an oxidation-reduction (redox) reaction:
6 C0 + 6 e- → 6 C-I (reduction)
2 I-I - 8 e- → 2 IIII (oxidation)
2 O-I + 2 e- → 2 O-II (reduction)
C6H10O5 is an oxidizing agent, KI is a reducing agent, H2O2 is an oxidizing agent.