Question

Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas?

Answer 1

Hydrogen gas is usually liberated when an acid reacts with a metal.

Take few pieces of zinc granules and add 5 ml of dilute H₂SO₄. Shake it and pass the gas produced into a soap solution. The bubbles of the soap solution are formed. These soap bubbles contain hydrogen gas.

H₂SO₄+Z_n → Z_nSO₄ + H₂ ↑

We can test the evolved hydrogen gas by its burning with a pop sound when a candle is brought near the soap bubbles.