At a given temperature $\mathrm{T},$ gases $\mathrm{N}\mathrm{e},\mathrm{ }\mathrm{A}\mathrm{r},\mathrm{ }\mathrm{X}\mathrm{e}$ and $\mathrm{K}\mathrm{r}$ are found to deviate from ideal gas behaviour. Their equation of state is given as $\mathrm{p}=\frac{\mathrm{R}\mathrm{T}}{\mathrm{V}-\mathrm{b}}$ at $\mathrm{T}.$ Here, $\mathrm{b}$ is the van der Waals constant. Which gas will exhibit steepest increase in the plot of $\mathrm{Z}$ (compression factor) vs $\mathrm{p}?$

• A

  $\mathrm{N}\mathrm{e}$
• B

  $\mathrm{K}\mathrm{r}$
• C

  $\mathrm{A}\mathrm{r}$
• Correct answer
  D

  $\mathrm{X}\mathrm{e}$

Solution

As the $\mathrm{b}$ increases the slope increases. We know that $\mathrm{b}$ represents the effective size of the molecules. Since, Xe has the biggest size among given noble gases because on moving down the group size increases due to increase in shell, hence Xe will have the highest slope.

Hence, the correct answer is option: 'D'.