posted by Jim .
How many grams of a 12.5% (w/w) aqueous solution of HCl do you have to measure out if yo need 32g Of HCl?
12.5% means 12.5 g HCl/100 g soln. So you want 32g of HCl.
You should take 100g soln x (32g/12.5g) = ? g soln.