Hydrochloric acid reacts with a metal X to form a gas Y which burns with a 'pop' sound. Sodium hydroxide solution also reacts with the same metal X (on heating) to form the same gas Y.

(a) Name X and Y


(b) Write the chemical equation of the reaction of metal X with


(i) hydrochloric acid, and


(ii) sodium hydroxide solution.

(a) Metal X is zinc; Gas Y is hydrogen.

(b) (i) When hydrochloric acid reacts with Zn, hydrogen gas and zinc chloride are formed Zn + 2HCl ZnCl2 + H2


(ii) Sodium hydroxide gives hydrogen gas and sodium zincate when reacts with zinc metal.


2NaOH + Zn Na2ZnO2 + H2


63