5 Na2(COO)2 + 2 NaMnO4 + 8 H2SO4 → 6 Na2SO4 + 2 MnSO4 + 10 CO2 + 8 H2O
This is an oxidation-reduction (redox) reaction:
2 MnVII + 10 e- → 2 MnII (reduction)
10 CIII - 10 e- → 10 CIV (oxidation)
NaMnO4 is an oxidizing agent, Na2(COO)2 is a reducing agent.