40.0 grams of Al2S3 are dissolved into 200ml of water yielding 220ml of solution, what is the percent strength of the solution?

Answer 1

%w/w, %w/v. From the way the problem is stated I assume you want %w/v.
% w/v = (grams solute/mL volume) x 100 = % w/v
(40/220)*100 = ?