5 HSVIO4- + Cr2VIO72- + 3 HSIVO3- 2 (CrIII)3+ + 8 SVIO42- + 4 H2O

This is an oxidation-reduction (redox) reaction:

3 SIV - 6 e- 3 SVI (oxidation)

2 CrVI + 6 e- 2 CrIII (reduction)

HSO3- is a reducing agent, Cr2O72- is an oxidizing agent.