Calculate the vapor pressure (in torr) at 298 K in a solution prepared by dissolving 38.5 g of the non-volatile non-electrolye urea {CO(NH2)2} in 142 g of methanol. The vapor pressure of methanol at 298 K is 122.7 torr. Give your answer to 2 decimal places.

The vapor pressure of methanol solution at 298K is 107.12 torr

Explanation:

As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.

The formula for relative lowering of vapor pressure will be,

where,

= relative lowering in vapor pressure

i = Van'T Hoff factor = 1 (for non electrolytes)

= mole fraction of solute  =

Given : 38.5 g of urea is present in 142 g of methanol

moles of solute (urea) =

moles of solvent (methanol) =

Total moles = moles of solute  + moles of solvent  = 0.64 + 4.4 = 5.04

= mole fraction of solute  =

Thus the vapor pressure of methanol solution at 298K is 107.12 torr

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.