Respuesta :
Explanation:
No. of moles of cholesterol solute, [tex]n_{1}[/tex] = 0.99 mol
No. of moles of toulene solvent, [tex]n_{2}[/tex] = 5.4 mol
Hence, total number of moles of solution will be as follows.
n = [tex]n_{1} + n_{2}[/tex]
= 0.99 mol + 5.4 mol
= 6.39 mol
Therefore, mole fraction of cholestrol solute ([tex]\chi_{1}[/tex]) is as follows.
= [tex]\frac{\text{no. of moles of chloesterol}}{\text{Total number of moles of solution (n)}}[/tex]
[tex]\chi_{1}[/tex] = [tex]\frac{0.99 mol}{6.39 mol}[/tex]
= 0.154
Vapor pressure of pure toulene solvent ([tex]p^{o}[/tex]) = 41 torr
Vapor pressure of solution = P
Hence, formula to calculate relative lowering of vapor pressure is as follows.
Relative lowering of vapor pressure = [tex]\frac{p^{o} - P}{p^{o}}[/tex]
As per relative lowering of vapor pressure colligative property, the relative lowering of vapor pressure is equal to the mole fraction of solute.
Hence, [tex]\frac{p^{o} - P}{p^{o}}[/tex] = [tex]\chi_{1}[/tex]
[tex]\frac{41 torr - P}{41 torr}[/tex] = 0.154
41 torr - P = 6.314
P = 34.686 torr
or, = 35 torr
Therefore, we can conclude that vapor pressure of the solution is 35 torr.
