Question

For a gas, the critical temperature and critical pressure are ${27}^0$C and $500$ atm respectively. The vander Waals constant b$\left(mo{l}^{-1}l\right)$ for the gas is?

• A. $6.15\times {10}^{-3}$
• B. $1.43\times {10}^{-3}$
• C. $49.2\times {10}^{-3}$
• D. $6.15\times {10}^{-2}$

Answer 1

Answer: (A)

$6.15\times {10}^{-3}$

Given $T_C={27}^{o}C=27+273=300K$

$P_C=500atm$, $R=0.0821atmL/mol/K$

$b=?$

$\Rightarrow b=\frac{R{T}_C}{8P_C}=\frac{0.0821\times 300}{8\times 500}$

$=0.00615$

$=6.15\times {10}^{-3}mo{l}^{-1}$