The second virial coefficient of nitrogen is $- 160 mL mo l^{- 1}$ at $100 K$ , $- 10 mL mo l^{- 1}$ at $300 K$ and $+ 21 mL mo l^{- 1}$ at $700 K$ . Which statements are correct?

AThe Boyle temperature of nitrogen lies between $300 K$ and $700 K$
BAt $100 K$ and $1 atm$ , $Z$ is approximately $0.98$ ( $R = 0.0821 L atm K^{- 1} mo l^{- 1}$ )
CAt $700 K$ the gas is more compressible than an ideal gas
DThe data show that attraction dominates at $300 K$ but only weakly

Answer: A, B, D

B

changes sign between

300

and

700 K

, so

T_{B}

lies in that interval (A true).

Z = 1 + BP / RT = 1 + \frac{( - 0.160 ) ( 1 )}{0.0821 \times 100} = 1 - 0.0195 = 0.9805 \approx 0.98

(B true). At

700 K

B

is positive, so

Z

exceeds 1 and the gas is less compressible than ideal (C false). At

300 K

B

is small and negative, so attraction dominates only slightly (D true).