Question

During the reaction of some metals with dilute hydrochloric acid,
following observations were made. Explain these observations giving
suitable reasons.
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.

Answer 1

Answer:

a. it is because silver is less reactive than hydrogen. it cannot displace hydrogen from dilute acid.

b. it is because the reaction is exothermic.

c.it is because sodium is highly reactive and forms hydrogen gas in the presence of moisture (h20) which catches fire as the reaction is highly exothermic and h2 is highly inflammable.

d.it is due to formation of hydrogen gas. the reaction becomes slow after some time as pbcl2(s) covers pb metal.