The vapour pressure of solution of 5g of non- electrolyte in 100g of water at a particular temperature is 2985 Nm-2. The vapour pressure of pure water at that temperature is 3000 Nm-2. The molecular weight of the solute is

2 0 2 3000 / H O P N m (vapour pressure of pure solvent) 2 2 2985 / H O P N m (vapour pressure of Solution) 2 2 100 18 / H O H O W g M g mol 5 B W g (wt of solute) B M M. wt of solute=? 2 2 2 2 2 0 0 3000 2985 5 18 3000 100 5 18 3000 100 15 180 / H O H O H O B H O H O B B B B P P W M P W M M M M g mole x x x x x x SOLUTIONS 67