2 Ag0 + 2 H2SVIO4 Ag2ISVIO4 + SIVO2 + 2 H2O

This is an oxidation-reduction (redox) reaction:

SVI + 2 e- SIV (reduction)

2 Ag0 - 2 e- 2 AgI (oxidation)

H2SO4 is an oxidizing agent, Ag is a reducing agent.