A 52.8-g sample of glucose (a nondissociated, nonvolatile solute with the formula C6H12O6) is dissolved in 158.0 g of water. What is the vapor pressure of this solution at 100°C?

Calculate the mole of glucose and water

The moles of water = 158g/18g/mol=8.778 moles

moles of glucose = 52.8g/180g/mol=0.293 moles

determine the mole fraction of the solvent

that is x solvent = 8.778 / (8.778+0.293) = 0.9677

use the Raults law to determine the vapor pressure

100 degree of water has a vapor pressure of 760 mmhg

p solution = (x solvent) (p^o solvent)

p solution=0.9677 x760 = 735.45 mmHg