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?

Explanation

When an acid reacts with a metal, then hydrogen gas is liberated. For example, when dilute sulphuric acid reacts with zinc granules, then granules, then hydrogen gas is liberated and zinc sulphate solution and formed:
`underset("Zinc")(Zn(s))+underset("Sulphuric acid")(H_(2)SO_(4)(aq))to underset("Zinc sulphate")(ZnSO_(4)(aq))+underset("Hydrogen")(H_(2)(g))`
The presence of hydrogen gas is tested by burning it. whjen a lighted match stick is brought near a gas jar containing hydrogengas, it burns with a pop sound making a little explosion.