Iqbal treated a lustrous,divalent element $M$ with sodium hydroxide. He observed the formation of bubbles in the reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas. Write chemical equations for both the reactions.

(N/A) The produced gas can be identified by bringing a burning matchstick near the mouth of the reaction vessel; it will produce a 'pop' sound,which confirms the presence of hydrogen gas $(H_2)$.
The chemical equation for the reaction with sodium hydroxide is:
$M + 2NaOH \rightarrow Na_2MO_2 + H_2 \uparrow$
The chemical equation for the reaction with hydrochloric acid is:
$M + 2HCl \rightarrow MCl_2 + H_2 \uparrow$
Since the element $M$ reacts with both acids and bases to release hydrogen gas,the element $M$ is an amphoteric metal (such as Zinc).