# Henry’s law constant for the molality of methane in benzene at 298 K is $4.27 \times 10^5$ mm Hg. Determine the solubility of methane in benzene at 298 K under 760 mm Hg.

$K_H=4.27\times 10^5mm$ Hg
P=760mm Hg
X=Solubility
$P=K_H.X$
$X=\large\frac{P}{K_H}=\frac{760}{4.27\times 10^5}$$=178\times 10^{-5}$
Hence (A) is the correct answer.