Mass Percent can be examined as the percentage of solute found within a given amount of solution.
Concept #1: Mass or weight percent is the percentage of a given element or compound within a solution.
Example #1: Calculate the amount of water (in kilograms) that must be added to 12.0 g of urea, (NH2)2CO, in the preparation of a 18.3 percent by mass solution. The molar mass of urea, (NH2)2CO, is 60.055 g/mol.
Example #2: A solution was prepared by dissolving 51.0 g of KBr in 310 mL of water. Calculate the mass percent of KBr in the solution.