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Question:

At a given temperature T, gases Ne, Ar, Xe, and Kr are found to deviate from ideal gas behavior. Their equation of state is given as p = RT/(V - b) at T. Here, b is the van der Waals constant. Which gas will exhibit the steepest increase in the plot of Z (compression factor) vs p?

Ar

Xe

Ne

Kr

Solution:

Correct option is C. Xe
Z = 1 + bP/RT
Y = mX + C
As b ↑ ⇒ slope ↑
We know that the 'b' is the volume occupied by the particles of the gas. Xe has the highest size so it occupies the highest volume for a certain amount of gases. Hence, Xe will have the highest slope.