Question

Assertion :The numerical values of $P_c,V_c,T_c$ are $\frac{a}{27b^2},3b$ and $\frac{8a}{27Rb}$ respectively. Reason: The compressibility factor $Z$ at critical conditions is $\frac{3}{8}$.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

The numerical values of the critical parameters $P_c,V_c,T_c$ are $\frac{a}{27b^2},3b$ and $\frac{8a}{27Rb}$ respectively.
At critical conditions, the expression for the compressibility factor becomes $\frac{R{T}_c}{P_c\cdot V_c}=\frac{R\times 8a\times 27b^2}{27Rb\times a\times 3b}=\frac{8}{3}$
Thus, both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.