Question

Calculate the mole fraction of methanol in a mixture of 10 mL methanol and 30mL ehtyl acetate.

Answer 1

If there are say two particles in the mixture A, B

Mole fraction is given

This the mole fraction of A in the mixture

nA- number of moles of A

nB - number of moles of B

Density of methanol = 0.79 g/mL

Density = Mass/Volume

Mass of 10 mL methanol = 10* 0.79= 7.9 g

Density of ethyl acetate = 0.90 g/mL

Mass of 30 mL ethyl acetate = 30* 0.90 = 27 g

Molecular mass of methanol = 32.04 au.

Molecular mass of ethyl acetate = 88.11 au.

Number of moles of methanol = 0.2465 moles

Number of moles of ethyl acetate = 0.3064 moles

Mole fraction of methanol = 0.2465/0.5529 = 0.445

Molefraction of ethyl acetate = 0.554

There is no unit for mole fraction.