Question

Assertion (A): Two moles of a given mass of a gas occupy a volume of 44.8 l at STP.

Reason (R): Volume of a mass of gas depends on temperature and pressure.

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

Answer 1

The correct option is D

A is false and R is true.

Explanation of correct option:

Assertion (A):

• We know that the volume of one mol ideal gas at STP is $22.4$l.
• In the question, it is not mentioned that the gas is ideal so, the above statement will not be valid for the given gas.

So, the assertion statement is false.

Reason (R):

• For any gas whether ideal or real, the volume of the gas depends upon pressure and temperature.
• The ideal gas equation is $\mathrm{PV}=\mathrm{nRT}$.
• The real gas equation is $(\mathrm{P}+\frac{{\mathrm{an}}^2}{{\mathrm{V}}^2})(\mathrm{V}-\mathrm{nb})=\mathrm{nRT}$.
• Where P= Pressure; T= temperature; n = No. of moles, R= Universal Gas Constant, a, b =Van der waal constant.
• So, from both the equation we can say that volume of a gas depends upon pressure and temperature.

So, the reason statement is true.

Hence, the correct option is (D).