MnO4 + 4 SO3 → Mn + 4 SO4
This is an oxidation-reduction (redox) reaction:
MnVIII + 8 e- → Mn0 (reduction)
4 SVI - 8 e- → 4 SVIII (oxidation)
MnO4 is an oxidizing agent, SO3 is a reducing agent.
Warning: Unknown compound 'MnO4'
Warning: Unknown compound 'SO4'