Answer:
The vapor pressure of solution is 23.1 Torr
Step-by-step explanation:
Colligative property of vapour pressure.
ΔP = P° . Xm
ΔP = Pressure of vapour from pure solvent - Pressure of vapour from solution
ΔP = P° - Ps
Xm = mole fraction of solute
Molar weight of glucose: 180 g/m
Moles of glucose = mass / molar weight → 76.6 g / 180 g/m = 0.425moles
If water volume is 250 mL, this volume is occupied by 250 g of solvent.
Density of water : 1g/mL
Molar weight of water: 18 g/m
250 g / 18g/m = 13.89 moles of solvent
Total moles = moles of solute + moles of solvent
0.425 + 13.89 = 14.315 moles
Mole fraction of solute = 0.425 / 14.315 = 0.029
23.8 Torr - Ps = 23.88 Torr . 0.029
Ps = 23.88 Torr . 0.029 - 23.8 Torr ⇒ 23.1 Torr