Solubility of a gas in water at STP is 0.2m. Henry's constant of the gas is equal to

pA=kAXA   .    .    .    1Given,Molality of the solution = 0.2mNumber of moles of solute = 0.2Weight of water = 1000gNumber of moles of water =100018At STP, pA=1 barXA=n2n1+n2; n2<<