During the reaction of some metals with dilute hydrochloric acid, following observations were made:


#1

During the reaction of some metals with dilute hydrochloric acid, following observations were made:
(i) Silver metal does not show any change.
(ii) The temperature of the reaction mixture rises when aluminium (Al) is added.
(iii) The reaction of sodium metal is found to be highly explosive.
(iv) Some bubbles of a gas are seen, when lead (Pb) is reacted with the acid.
(v) A gas is produced when sodium carbonate is added to the acid.
Explain these observations giving suitable reasons.


#2

(i) Silver is a very less reactive metal (as it placed below hydrogen in reactivity series). Thus, it does not react withdil. HCl.
(ii) The reaction of Al with dil. HCl is exothermic, i.e. heat is produced in the reaction, hence the temperature of the reaction mixture rises.
(iii) Sodium is a very reactive metal. It reacts vigorously with the evolution of heat too.
(iv) Bubbles are seen due to the evolution of H2 gas.

(v) CO2 gas is produced when Na2C03 reacts with dil. HCl.