Question

With the help of an acitivity show that the heating of lead nitrate is an endothermic reaction and addition of water in quick lime is exothermic reaction​

Answer 1

Option (A) is correct.

(i) Reaction of water with quick lime is exothermic reaction.When water is added to quicklime, then calcium hydroxide is formed with large amount of heat is released in the process.

(ii) Dilution of an acid is exothermic reaction.On formation of any kind of bond, energy is released. Hence, when we add water in acid, heat is evolved due to formation of hydrogen bond between water and acid.

(iii) Evaporation of water is endothermic reaction because water molecules must absorb heat from the surroundings to increase their kinetic energy.

(iv) Sublimation of camphor (crystals) is endothermic reaction. Phase changes like that absorb heat because gaseous molecules are in a higher energy state than solid particles.