This is an oxidation-reduction (redox) reaction:
2 HI + 4 e- → 2 H-I (reduction)
Fe0 - 2 e- → FeII (oxidation)
2 O-I - 2 e- → 2 O0 (oxidation)
H2O2 is an oxidizing agent, Fe is a reducing agent, H2O2 is a reducing agent.
Reactants:
Products: