Question

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

Answer 1

Exothermic reaction: The reaction which is accompanied with evolution of heat is known as exothermic reaction. 

CaO + CO₂ → CaCO₃, ΔH= -178.3 kJ mol^-1 

Endothermic reaction: The reaction which is accompanied with absorption of energy is known as endothermic reaction, e.g., 

2NH₃ → N₂ + 3H₂; ΔH = +91.8 kJ mol^-1