Mo + 2 NaNO3 + 2 NaCO3 → Na2MoO4 + 2 NaNO2 + 2 CO2
This is an oxidation-reduction (redox) reaction:
Mo0 - 6 e- → MoVI (oxidation)
2 CV + 2 e- → 2 CIV (reduction)
2 NV + 4 e- → 2 NIII (reduction)
Mo is a reducing agent, NaCO3 is an oxidizing agent, NaNO3 is an oxidizing agent.
Warning: Unknown compound 'NaCO3'. Did you mean NaCo3?