Match the gases under specified conditions listed in Column I with their properties/laws in Column II. Indicate your answer by darkening the appropriate bubbles of \(4 \times 4\) matrix given in the ORS.

Column I	Column II
A. Hydrogen gas \((P=200 atm,\) \(T=273 K)\)	p. Compressibility factor \(\neq 1\)
B. Hydrogen gas \((P \sim 0,\) \(T=273 K)\)	q. Attractive forces are dominant
C. \(CO _2(P=1 atm,\) \(T=273 K)\)	r. \(P V=n R T\)
D. Real gas with very large molar volume	s. \(P(V-n b)=n R T\)

(A) \(-p, s(\mathrm{~B})-r\) (C) \(-p, q\) (D) \(-r\)
Explanation van der Waals' equation
\(
\left(p+\frac{n^2 a}{V_m^2}\right)\left(V_m-b\right)=n R T
\)
For hydrogen gas \((p=200 \mathrm{~atm}, T=273 \mathrm{~K})\)
As pressure is large \(V_m\) can be assumed small, thus ' \(b\) ' can not be ignored, while due to high pressure \(a / V_m^2\) can be considered negligible in comparison to \(p\).
\(
p\left(V_m-b\right)=R T \quad \text { and } \quad Z=1+\frac{p b}{R T}
\)
For hydrogen gas \((p \sim 0, T=273 \mathrm{~K})\)
when pressure occurs of low about \(1 \mathrm{~atm}\) or less and temperature is not very close to the point of liquification \(\left[T_c\left(\mathrm{H}_2\right)=33.3 \mathrm{~K}\right]\) gas behaves ideally.
For
\(
P V=n R T
\)
Temperature is close to the point of liquification \(\left[T_C\left(\mathrm{CO}_2\right)=304.2\right]\) thus, deviation from ideality appears very high (due to high attractive force of attraction).
For real gas with very large molar volume.
As molar volume is very large \(a / V_m^2\) will be negligible and at the same time ' \(b\) ' in comparison to \(V_m\) is also considered negligible, thus, \(p V_m=n R T\)