Question

Assertion (A): At critical temperature, surface tension of a liquid becomes zero.
Reason (R) : At this temperature intermolecular forces for liquid and gases become equal. Liquid can expand without any restriction.

• A. Both Assertion (A) and Reason (R) are true and the Reason (R) is correct explanation of the Assertion(A) .
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not correct explanation of the Assertion(A) .
• C. Assertion (A) is true, but the Reason (R) is false.
• D. Assertrion (A) is false, but the Reason (R) is true.

Answer 1

The correct option is A Both Assertion (A) and Reason (R) are true and the Reason (R) is correct explanation of the Assertion(A) .

The temperature at which force of attraction between molecules is negligibly small or equal to that of gases is critical temperature.
At this temperature as forces are negligibly small, surface tension is zero.