Ncert Exercises & Solutions

Given below are two statements:

Assertion (A):	At constant temperature, pV vs p plot for real gases is not a straight line.
Reason (R):	At high pressure, all gases have Z>1 but at an intermediate pressure most gases have Z<1.

1.	Both (A) and (R) are true and (R) is the correct explanation of (A).
2.	Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.	(A) is true but (R) is false.
4.	(A) is false but (R) is true.

Hint: For real gas Z is not equal to 1.

At constant temperature, pV vs p for real gases is not a straight line because real gases have intermolecular forces of attraction.

At high pressure, all gases have Z>1 but at an intermediate pressure, most gases have Z<1 is a correct statement.

Hence, both assertion and reason are true and the reason is not the correct explanation of assertion.