What do you understand by exothermic reaction and endothermic reaction? Give one example of each type.

Exothermic reaction- The reaction in which heat is evolved is called exothermic reaction.

for example,

CaO + CO₂→ CaCO₃ ΔH=-178kJmol^-1

Endothermic reaction- The reaction in which heat is absorbed is called endothermic reaction.

for example,

2NH₃ → 3N₂+ H₂ ΔH=918kJmol^-1