posted by Li .
What mass in grams of an aqueous hydrochloric acid solution that is 37.0% by mass hydrogen chloride is needed to supply 2.000 moles of hydrogen chloride?
37.0% w/w means 37.0g HCl/100 g soln. You want 2.00 moles x molar mass HCl = x g HCl.
100 g soln*(x g /37) = mass soln to be taken.