2 NaNO3 (aq) + 6 FeSO4 (aq) + 4 H2SO4 (aq) → Na2SO4 (aq) + 3 Fe2(SO4)3 (s) + 2 NO (g) + 4 H2O (l)
This is an oxidation-reduction (redox) reaction:
2 NV + 6 e- → 2 NII (reduction)
6 FeII - 6 e- → 6 FeIII (oxidation)
NaNO3 is an oxidizing agent, FeSO4 is a reducing agent.
This is a precipitation reaction: Fe2(SO4)3 is the formed precipitate.
This is a gas evolution reaction, NO is the formed gas.