Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Helium is used to dilute oxygen in diving apparatus.
Reason R: Helium has high solubility in O2.
In the light of the above statements, choose the correct answer from the options given below.

• A. Both A and R are true but R is NOT the correct explanation of A.
• B. A is true but R is false.
• C. A is false but R is true.
• D. Both A and R are true and R is the correct explanation of A.

Answer 1

Answer: (B)

A is true but R is false.

Answer 2

The correct option is (B): A is true but R is false.

Explanation:

Assertion A states that helium is used to dilute oxygen in the diving apparatus. This is true. Helium is often used as a diluent gas in diving mixtures because it has a low density and does not react with other gases. Adding helium to the breathing gas mixture, it helps reduce the density and minimize the risk of nitrogen narcosis, which can occur at greater depths when breathing air with high nitrogen content.

Reason R states that helium has a high solubility in O2. This statement is incorrect. In reality, helium has low solubility in oxygen. Unlike nitrogen, helium does not dissolve significantly in oxygen under normal conditions. This low solubility is one of the reasons why helium is preferred over nitrogen in diving mixtures.

Since Reason R is incorrect, the correct answer would be option (b), where Assertion is correct.