small quantities of hydrogen gas can be prepared by the addition of hydrochloric acid to zinc?
Small quantities of hydrogen gas can be prepared in the laboratory by the addition of aqueous hydrochloric acid to metallic zinc. Zn(s)+2HCl(aq)⟶ZnCl2(aq)+H2(g) Typically, the hydrogen gas is bubbled through water for collection and becomes saturated with water vapor.