P Block Elements

Argon is used in high-temperature welding and operations that require a non-oxidising atmosphere along with the absence of nitrogen.

Thus, option A) is the correct answer.

To solve this question, we need to identify the gas that is liberated when a salt containing chloride is treated with concentrated sulfuric acid. Let's examine the reaction:

When a chloride salt (e.g., NaCl) is treated with concentrated sulfuric acid (H₂SO₄), the following reaction occurs:

In this reaction, hydrogen chloride gas (HCl) is liberated, which is a colorless gas. This accurately matches the description in the question.

Let's examine the incorrect options:

• Chlorine gas: Chlorine gas is a greenish-yellow gas, not colorless, and is typically produced in other chemical reactions, such as when HCl is oxidized.
• Sulphur dioxide gas: This gas is generally produced in reactions involving the complete reduction of H₂SO₄, not when reacting with a simple chloride salt.
• Hydrogen gas: Hydrogen gas is colorless, but it is not produced in this specific reaction involving chloride salts and concentrated sulfuric acid.

Therefore, the correct answer is Hydrogen chloride gas.

1. Analyzing the Reaction:
In the detection of the II group acid radical (chlorides), when a salt containing chloride ions is treated with concentrated sulphuric acid, a colourless gas is liberated. This gas is hydrogen chloride (HCl) gas, which is characteristic of reactions involving chloride salts and concentrated sulphuric acid.

2. Identifying the Gas:
The reaction results in the release of hydrogen chloride gas (HCl), which is a colourless gas with a pungent odor. It is produced by the reaction of the chloride salt with concentrated sulfuric acid.

Final Answer:
The name of the gas is (A) "Hydrogen chloride gas."