Question

Glycerol (C3H8O3), also called glycerine, is widely used in the food and pharmaceutical industries. Glycerol is polar and dissolves readily in water and polar organic solvents like ethanol. Calculate the mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol (CH3CH2OH; density

Answer 1

Answer: The mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol is 0.93

Step-by-step explanation:

Given : Volume of ethanol (solvent) = 21.10 ml

density of ethanol (solvent)= 0.789 g/ml

Mass of ethanol (solvent) =
`0.789g/ml* 21.10ml=16.6g`

Mass of glycerol (solute) = 2.51 g

Mole fraction of a component is the ratio of moles of that component to the total moles present.

moles of ethanol =
`\frac{\text {given mass}}{\text {molar mass}}=(16.6g)/(46g/mol)=0.36mol`

moles of glycerol =
`\frac{\text {given mass}}{\text {molar mass}}=(2.51g)/(92g/mol)=0.027mol`

mole fraction of ethanol (solvent) =
`\frac{\text {moles of ethanol}}{\text {moles of ethanol + moles of glycerol}}=(0.36)/(0.36+0.027)=0.93`

The mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol is 0.93