Question

Calculate the mole fraction of ethanol and water in a sample of rectified spirit which contains 46% ethanol by mass ? [Ans-0.25,0.75]

Answer 1

The answer is in the image. Please comment if unclear.

Answer 2

Answer:Mole fraction of ethanol is 0.25.

Mole fraction of water is 0.75.

Explanation:

Rectified spirit which contains 46% ethanol by mass.

In 100 g spirit has 46 grams of ethanol and 54 grams of water.

Moles of ethanol=$n_e=\frac{46 g}{46 g/mol}=1 mol$

Moles of water $n_w=\frac{54 g}{18 g/mol}= 3 mol$

$\chi_e=\frac{n_e}{n_e+n_w}=\frac{1}{1+3}=0.25$

$\chi_w=\frac{n_w}{n_e+n_w}=\frac{3}{1+3}=0.75$

Mole fraction of ethanol is 0.25.

Mole fraction of water is 0.75.