2 K2CrO4 + 6 FeSO4 + 8 H2SO4 → 3 Fe2(SO4)3 + Cr2(SO4)3 + 8 H2O + 2 K2SO4
This is an acid-base reaction (neutralization): K2CrO4 is a base, H2SO4 is an acid.
This is an oxidation-reduction (redox) reaction:
2 CrVI + 6 e- → 2 CrIII (reduction)
6 FeII - 6 e- → 6 FeIII (oxidation)
K2CrO4 is an oxidizing agent, FeSO4 is a reducing agent.