Chemistry: The Molecular Science (5th Edition)

$V=2.00\,L$ $n= 7.0\,mol$ $T=(50+273)K=323\,K$ $R=0.0821\,L\,atm\,mol^{-1}K^{-1}$ For $CO_{2}$, $a=3.59\,L^{2}\,atm/mol^{2}$ and $b=0.0427\,L/mol$ $(P+\frac{n^{2}a}{V^{2}})(V-nb)=nRT$ (van der Waals equation) $\implies P=(\frac{nRT}{V-nb})-(\frac{n^{2}a}{V^{2}})$ $=[\frac{(7.0\,mol)(0.0821\,L\,atm\,mol^{-1}K^{-1})(323\,K)}{2.00\,L-(7.0\,mol\times0.0427\,L/mol)}]-[\frac{(7.0\,mol)^{2}(3.59\,L^{2}\,atm/mol^{2})}{(2.00\,L)^{2}}]$ $=65\,atm$