Question

A solution is prepared by dissolving 22.8 mL of methanol (d = 0.782 g/mL) in 100 mL of water (d = 1.00 g/mL) so that the final volume of solution is 118 mL. What is the percent methanol by mass?

Answer 1

22.8 mL methanol x 0.782 g/mL = grams methanol.
mass soln = mass methanol + mass H2O
%methanol w/w = (mass methanol/total mass soln)*100 = ??