Question

The Vander Waal's parameters for gases W, X, Y and Z are

Gas	a (atm L2 mol–2)	b (L mol–1–11–1–14545454)
W	4.0	0.027
X	8.0	0.030
Y	6.0	0.032
Z	12.0	0.027

Which one of these gases has the highest critical temperature.

• A. W
• B. X
• C. Y
• D. Z

Answer 1

Answer: (D)

Z

Answer 2

For Z gas of given gases, critical temperature is highest

$T_{c} = \frac{8a}{27Rb} \Rightarrow T_{C} = \frac{8 \times 12}{27 \times 0.821 \times 0.27} = 1603.98K$