Question

Which gas is liberated when an acid reacts with a metal? 

• A. Hydrogen
• B. Oxygen
• C. Carbon dioxide
• D. Nitrogen Correct Answer: (A) Hydrogen Solution:

Hint:

Metal + Dilute Acid \(\rightarrow\) Salt + Hydrogen Gas Hydrogen can be identified by the characteristic "pop" sound when a burning splint is brought near it.

Answer 1

The Correct Option is A

Step 1: Recall the general reaction.
When a metal meets a dilute acid, it pushes out hydrogen and forms a salt.
\[ \text{Metal} + \text{Acid} \rightarrow \text{Salt} + H_2 \]

Step 2: Look at a real example.
Zinc with hydrochloric acid gives off hydrogen gas.
\[ Zn + 2HCl \rightarrow ZnCl_2 + H_2 \]

Step 3: Name the gas.
The gas set free is hydrogen. You can test it by the soft pop sound it makes near a flame.
\[ \boxed{\text{Hydrogen}} \]