Question

Give two e.g. of reactions where heat is liberated

Answer 1

Combustion reactions of fuels or a substancee.g.Burning of natural gas: {\displaystyle {\ce {CH4 + O2 -> CO2 + 2H2O}}}{\displaystyle {\ce {C6H12O6 + 6O2 -> 6CO2 +6H2O}}}