Question

For this exercise, we will consider a solution of the nonvolatile solvent ethylene glycol, C2H4(OH)2, in water. If the solution contains 1 mol of C2H4(OH)2 for each 4 mol of H2O, what is the mole fraction of water?

Answer 1

Answer:

Mole fraction of water is 0.8.

Explanation:

Mole fraction is defined as ratio of moles of single component to the sum of moles of all components present in the solution.

Moles of ethylene glycol = $n_1=1 mol$

Moles of water = $n_2=4 mol$

Mole fraction of ethylene glycol = $\chi_1=\frac{n_1}{n_1+n_2}$

$\chi_1=\frac{1 mol}{1 mol+4 mol}=0.2$

Mole fraction of water  = $\chi_2=\frac{n_2}{n_1+n_2}$

$\chi_2=\frac{4 mol}{1 mol+4 mol}=0.8$