Describe briefly the laboratory preparation of hydrogen gas and write a chemical equation for the reaction

Answer 1

Hydrogen gas can be prepared in the laboratory by the reaction of an acid with a metal. A common method is to react zinc metal with dilute hydrochloric acid.

Procedure:

1. In a beaker, add a small piece of zinc metal.
2. Gradually add dilute hydrochloric acid to the beaker.
3. Bubbles of hydrogen gas will form as the reaction proceeds.

Chemical Equation: The balanced chemical equation for this reaction is:

\[ \text{Zn (s)} + 2 \text{HCl (aq)} \rightarrow \text{ZnCl}_2 (aq) + \text{H}_2 (g) \]

This shows that zinc reacts with hydrochloric acid to produce zinc chloride and hydrogen gas.