Suppose that a 120.0 g solution contains 100.0 g of water and 20.0 g of dissolved sugar.

What is the approximate concentration of sugar in the solution, by mass?

83.3%

20.0%

16.7%

14.3%

We are given a 120-g solution containing 100 grams of water as the solvent and 20 grams of dissolved sugar as the solute. In this case, we just have to divide the mass of sugar by the total mass of the solution then multiply by 100 percent. Hence, 20 / 120 * 100% is equal to 16.7 percent.