Consider two gases: X with $a = 0.03 L^{2} atm mo l^{- 2}$ , $b = 0.024 L mo l^{- 1}$ , and Y with $a = 5.5 L^{2} atm mo l^{- 2}$ , $b = 0.030 L mo l^{- 1}$ . Which statements are correct?

Answer: A, B, C

Larger

a

means stronger attraction and easier liquefaction (A true).

T_{B}

of X

= a / R b = 0.03/ (0.0821 \times 0.024) = 15 K

, far below room temperature, so repulsion dominates everywhere (B true).

T_{c} \propto a / b

: ratio

= (5.5/0.030) / (0.03/0.024) = 147

(C true).

V_{c} = 3 b

is larger for Y (D false).