Question

(a) How will you test for the gas which is liberated when hydrochloric acid reacts with an active metal?
​(b) Name any two active metals which can be used with hydrochloric acid to liberate the same gas.

Answer 1

(a) When hydrochloric acid is treated with an active metal then hydrogen gas is released.
$2\mathrm{M}+2\mathrm{HCl}\to 2\mathrm{MCl}+{\mathrm{H}}_2$
When this hydrogen gas comes in contact with burning match stick then the gas burns with a pop sound.

(b) Sodium and potassium are two active metals which can be used with hydrochloric acid to liberate the hydrogen gas.