What happens when an acid reacts with a metal? Give chemical equation of the reaction involved. (b) Which gas is usually liberated when an acid reacts with a metal? How will you test for the presence of this gas?

(a) When an acid reacts with a metal, then a salt and hydrogen gas are formed.

→ ZnCl2 + H2

Zn(s) + 2HCl(aq)

(b) Hydrogen gas is liberated when acid reacts with metal. It is observed that a formation of gas bubbles along the surface of the metal. The obtained bubbles is then passed through a soap solution and when a burning candle is brought near to the bubble the gas present in the soap bubble will burns with a pop sound and hence it can be concluded that it is hydrogen because only hydrogen gas can make a pop sounds when it burns