At moderate pressure van der Waals equation is given as :
$\left(P+\frac{an^{2}}{V^{2}}\right)\left(V\right)=nRT$$\left(P+\frac{1.4}{\left(0.1\right)^{2}}\right)\left(0.1\right)=1\times0.082\times300$$\left(P + 140\right) ??0.1 = 24.6$$0.1 P + 14 = 24.6$$0.1 P = 10.6 \Rightarrow P = 106$ atm