During the reaction of some metals with dilute hydrochloric acid, following observations were made. (i) The temperature of the reaction mixture rises when aluminium (Al) is added. (ii) The reaction of sodium metal is found to be highly explosive. (iii) Some bubbles of a gas are seen when lead (Pb) is reacted with the acid. Explain these observations giving suitable reasons.

(i) When aluminium reacts with dilute hydrochloric acid, it releases hydrogen gas and heat, causing the temperature to rise due to the exothermic nature of the reaction.

(ii) Sodium reacts violently with dilute hydrochloric acid, producing hydrogen gas and heat, which can ignite the gas, leading to an explosive reaction.

(iii) When lead reacts with dilute hydrochloric acid, it produces hydrogen gas as well, but the reaction is slower and less vigorous than that of aluminium or sodium, resulting in the formation of bubbles of gas.