12 H2SO4 (aq) + 8 KMnO4 (aq) + 5 C2H2 (g) → 12 H2O (l) + 4 K2SO4 (aq) + 8 MnSO4 (aq) + 5 C2H2O4 (aq)
This is an oxidation-reduction (redox) reaction:
8 MnVII + 40 e- → 8 MnII (reduction)
10 C-I - 40 e- → 10 CIII (oxidation)
KMnO4 is an oxidizing agent, C2H2 is a reducing agent.