C6H12O6 (aq) + 12 KNO3 (aq) → 12 KNO2 (aq) + 6 CO2 (g) + 6 H2O (l)
This is an oxidation-reduction (redox) reaction:
6 C0 - 24 e- → 6 CIV (oxidation)
12 NV + 24 e- → 12 NIII (reduction)
C6H12O6 is a reducing agent, KNO3 is an oxidizing agent.
This is a gas evolution reaction, CO2 is the formed gas.