2 KI (aq) + H2SO4 (aq) → K2SO3 (aq) + I2 (s) + H2O (l)
This is an oxidation-reduction (redox) reaction:
SVI + 2 e- → SIV (reduction)
2 I-I - 2 e- → 2 I0 (oxidation)
H2SO4 is an oxidizing agent, KI is a reducing agent.
This is a precipitation reaction: I2 is the formed precipitate.