Question

17) How many grams of water are in 250.0 g of a 5% by mass solution? How many grams of sugar are in this solution? 18) A solution is prepared with 45.0 g of NaCl in enough water to make a 50mL solution. What is the molarity of the solution? 19) If 345 g of MgCl, solution is evaporated and 32.8 g of magnesium chloride are collected. What is the mass percent of the salt in the solution? How much water was boiled off? 20) If 15.0 mL of methanol (CH,OH) are added to enough water to make a 50.0 mL solution, what is the volume percent of the solution? How much water was added?

Answer 1

17.) x 100 5 * 100 Mass mass Total of sugar (x) mass of colution = x R4 - = 5 x 100 5 s x = 12.5 gm mass of sugar in eolution = 12.5 gm mass of water = (250-12.50 = 237.5 gm and - 18.) Molarity of solution moles volunne of colute of solution (2) 0.7692 45 23 +35.5 50 Too 0.05 - 15.384 M 19.) Mass percent of all, = mass of Malle Total mass of colution 100 = 32.8 x 100 345 = 9.5070. 20) Volume percent 15 x 100 = 30% 80 water added = (50-15) mL = 35 mL

The answers to all your 4 questions are given above