2 HIO3 (aq) + 10 FeSO4 (aq) + 5 H2SO4 (aq) → I2 (s) + 5 Fe2(SO4)3 (s) + 6 H2O (l)
This is an oxidation-reduction (redox) reaction:
2 IV + 10 e- → 2 I0 (reduction)
10 FeII - 10 e- → 10 FeIII (oxidation)
HIO3 is an oxidizing agent, FeSO4 is a reducing agent.
This is a precipitation reaction: I2 andFe2(SO4)3 is the formed precipitate.