Given, 16 g CH3=1616=1 mole
Applying van der Waal's equation,
(P+n2aV2)(V−nb)=nRT
P=nRT(V−nb)−n2aV2
Substituting n=1,
R=0.0821 L atm K−1mol−1;T=300 K;V=0.250 L;
a=2.253 atm L−2mol−2;b=0.0428 L mol−1
P=1×0.0821×300(0.250−1×0.0428)−1×2,253(0.250)2=82.822 atm
The ideal gas equation predicts that,
P=nRTV=1×0.0821×3000.250=98.52 atm