Question

For $NO$ and $CC{l}_4$, the values of $P_c$ and $T_c$ are given below:

Molecules	$T_c$	$P_c$
$NO$	177 K	6.485 atm
$CC{l}_4$	550 K	4.56 atm

Select the correct statement(s).

• A. $CC{l}_4$ has smaller value of van der Waal constant.
• B. $NO$ gas has larger value of van der Waal constant.
• C. $CC{l}_4$ has larger critical volume as compared to $NO$.
• D. $NO$ gas shows less deviation from ideal behaviour than $CC{l}_4$.

Answer 1

Answer: (C), (D)

The correct options are
C $CC{l}_4$ has larger critical volume as compared to $NO$.
D $NO$ gas shows less deviation from ideal behaviour than $CC{l}_4$.

(C)

The critical temperature of $CC{l}_4$ is higher than the critical temperature of NO.
The critical pressure of $CC{l}_4$ is lower than the critical pressure of NO.
Hence, the critical volume of $CC{l}_4$ (which is equal to the ratio of the critical temperature to the critical pressure) is larger than the critical volume of NO.
Thus, option C is correct.

(D)
$V_c=3b$
$V_c=\frac{3R{T}_c}{8P_c}$
Hence, $b=\frac{R{T}_c}{8P_c}$
For NO, the value of the critical temperature is lower than the value for $CC{l}_4$.
Also, for NO, the value of the critical pressure is higher than the value for $CC{l}_4$.
Hence, the value of b is lower for NO than for $CC{l}_4$.
Thus, NO gas shows less deviation from ideal behavior than $CC{l}_4$.
Option D is correct.

Options A and B are incorrect.