Question

Calculate the mole fraction of ethanol in solution prepared by

dissolving 46 g of ethanol in 90 g of water.

[Molar mass of ethanol = 46 u]​

Answer 1

Answer:

Ethanol 46 g/mol

Water 18 g/mol

Calculate moles of ethanol: 14.6 grams x 1 mol / 46 grams = 0.317 moles

Calculate moles of water: 53.6 grams x 1 mol / 18 grams = 2.98 moles

Mole fraction = moles of component / total moles in solution

= 0.317 / (0.317 + 2.98) = 0.0963

Answer 2

Given - Weight of ethanol - 46 gram

Weight of water - 90 gram

Molecular weight of ethanol - 46 gram

Find - Mole fraction of ethanol in solution.

Solution - Mole fraction is calculated by the help of formula -

Number of moles of component/ total number of moles in solution.

Number of moles are calculated by the formula - weight / molecular weight.

Number of moles of ethanol - 46/46

Number of moles of ethanol - 1

Molecular weight of water - 18 gram

Number of moles of water - 90/18

Number of moles of water - 5

Mole fraction of ethanol - 1 / (5 + 1)

Mole fraction of ethanol - 1/6

Mole fraction of ethanol - 0.16

Hence, mole fraction of ethanol is 0.16.