Given :
Henry’s law constant = K
= 4.27 × 10-5 mm Hg mol dm-3
Pressure of the gas = P = 760 mm Hg
KH = 4.27 × 10-5 mm-1 mol dm-3
= 4.27 × 10-5 × 760 atm-1 mol dm-3
= 3245 × 10-5 atm-1 mol dm-3
P = 760 mm = \(\frac{760}{760}\) = 1 atm
By Henry’s law,
S = KH x P = 3.245 x 10-2atm-1 mol dm-3 x 1 atm
= 3.245 × 10-2 mol dm-3
∴ Solubility of methane = 3.245 × 10-2 mol dm-3