C2-IH2 + K2Cr2VIO7 CrIIICIIIO3 + Cr0 + K2CIVO3 + H2O

This is an oxidation-reduction (redox) reaction:

C-I - 5 e- CIV (oxidation)

C-I - 4 e- CIII (oxidation)

CrVI + 6 e- Cr0 (reduction)

CrVI + 3 e- CrIII (reduction)

C2H2 is a reducing agent, C2H2 is a reducing agent, K2Cr2O7 is an oxidizing agent, K2Cr2O7 is an oxidizing agent.