Question 2 Page 22 - Chapter 2 Class 10 - Acids, Bases and Salts

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

The reaction of Acids and Metal leads to the formation of a salt. Hydrogen being common to all acids gets displaced in the reaction and is evolved as hydrogen gas.

For Example : When Zinc (Zn)  reacts with dilute Sulphuric Acid (H ₂ SO ₄ ) , it produces a salt called Zinc Sulphate (ZnSO ₄ )  and Hydrogen Gas.

The characteristic of Hydrogen gas is that it burns with a pop sound.Hence, to check the presence of H ₂ gas, bring the flame of a burning candle near the mouth of the container where the reaction is taking place. If a pop sound is heard, then the presence of H ₂ gas is confirmed.