Gaseous state

b(6)
Ans(a): 1.98%
(B): 10.156 litres
Please give explaination

T = 273.15 + 20 = 293.15 KP (N2) = P = 745 mm Hg P (Water) = 760 – 745 = 15 mm Hg
Lets assume that the portion of nitrogen is Xn, then as per the concept of partial pressure,P(N2) = Xn x P = 745 / 760 = 0.98
Hence, the percentage of mole = 98%Mass of water vapor = Increases in weight of drying agent = 0.15gP(water) = 15 mm Hg exerted by 0.15 g of water,
then by formula
V = nRT/P= [(0.15/18) x (8.205 x 102 x 293.15)]/(15/760)= 10.2 L