Discuss the factors that affect a chemical change.

What do you observe in the following cases?

(a) Lead nitrate is heated.

(b) Silver chloride is exposed to sunlight.

(c) Hydrogen peroxide is exposed to sunlight

(d) H₂S gas is passed through copper sulphate solution

(e) Barium chloride is added to sodium sulphate solution.

(f) Water is added to quick lime

(g) Sodium chloride solution is added to silver nitrate solution.

State the effects of endothermic and exothermic reactions on the surroundings with examples.