115) The vapour pressure of a pure liquid A at 310^oC is 120 torr. The vapour pressure of this liquid in solution with liquid B is 72 torr. Calculate the mole fraction of A in solution, if the mixture obeys Raoult′s law:

116) If latent heat of fusion of ice is 80 cal⁄gm at 0^oC, calculate molal depression constant for water:

117) Calculate the molal elevation constant of water that evaporates at 100^oC with the absorption of 536 cal⁄gm: (R = 2 cal)

118) 15 gm of methyl alcohol is dissolved in 35 gm of water. What is the mass percentage of methyl alcohol in solution?

119) Osmotic pressure of a sugar solution at 24^oC is 2.5 atm. Determine the concentration of the solution in gm mol⁄L: