Question

The mole fraction of benzene in a solution in Toluene is 0.40. Calculate the weight percent of benzene in the solution.

Answer 1

Step 1:

Mol. wt. of benzene = 78 g
Mol. wt. of toluene = 92 g

Basis of calculations:

1 mole of mixture Benzene = 0.4 mol = $78\times 0.04g$ = 31.2 g
Toluene = 0.6 mole = $92\times 0.06g$ = 55.2 g
Total weight of mixture = 31.2 + 55.2 g = 86.4 g
Weight % of benzene = $\frac{31.2}{86.4}\times 100=36.1\%$