Question

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

Answer 1

a) because silver is a less reactive element
b) because reaction of alluminium with hydrochloric acid is exothermic reaction
c) as sodium is very reactive element so it reacts vigorously with HCl and is found to be explosive
d) bubbles of hydrogen gas are seen when lead reacts with hydrochloric acid

Answer 2

A) silver bring a less reactive metal than hydrogen does not displace hydrogen from HCL hence it does not react with dilute HCL

B) it is a exothermic reaction

C) it is an exothermic reaction

D) when lead is treated with hydrochloric acid bubbles of hydrogen gas are evolved

Pb+2Hcl--------- pbcl2 +H2