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?
When an acid react with a metal it liberates hydrogen gas. E.g., Zn(s) + 2HCl(aq) → ZnCl2 (aq) + H2(g) To test the presence of H2 gas, bring a burning splinter near the mouth of the test tube where H2 gas is released, the match stick bums with a pop sound.
