Question

The vapour pressure of water at 20°C is 17.5mm Hg. If 18g of glucose (C₆ H₁₂O₆ ) is added to 178.2g of water at 20°C, the vapour pressure of the resulting solution will be
(a) 17.325mm Hg 

(b) 17.675mm Hg

(c) 15.750mm Hg 

(d) 16.500mm Hg

Answer 1

(a) : In solution containing nonvolatile solute,pressure  is directly proportional to its mole fraction.
P_solution = vapour pressure of its pure component × mole fraction in solution

P_solution = 17.32​