The product formed in the following reaction will be:
2KHCO3+H2SO4→
K2SO4+CO2
K2SO4+2H2O+2CO2
K2SO4+H2O
K2SO4+H2S+CO2
Reaction of carbonates and bicarbonates with sulphuric acid results in the formation of salt, water and carbon dioxide gas.
2KHCO3+H2SO4→K2SO4+2H2O+2CO2