At $320 K$ and $25 atm$ the compressibility factor of a gas is $0.88$ ( $R = 0.0821 L atm K^{- 1} mo l^{- 1}$ ). Which statements are correct?

AIts molar volume is 12 percent smaller than that of an ideal gas at the same $P$ and $T$
BIts molar volume is about $0.925 L mo l^{- 1}$
CIf the pressure were calculated from the ideal gas law at this molar volume and temperature, it would be about $28.4 atm$
DThe gas is above its Boyle temperature

Answer: A, B, C

V_{real} / V_{ideal} = Z = 0.88

, a 12 percent reduction (A true).

V_{m} = ZRT / P = 0.88 \times 26.272/25 = 0.9248 L mo l^{- 1}

(B true).

P_{ideal} = RT / V_{m} = 26.272/0.9248 = 28.41 atm

, i.e.

P / Z

(C true).

Z

below 1 at moderate pressure means attraction dominates, which requires

T

below

T_{B}

(D false).