A solution's mass-mass percent concentration is given as the mass of the solute divided by the mass of the solution, which is then multiplied by 100 percent. The mass of the solution is equal to the mass of the solvent added to the mass of the solute.
For example, if given a solution that contains 5.0 grams of a solute and 110.0 grams of solvent, then the mass-mass percent concentration of the solute is 5.0 grams/(5.0 +110.0) x 100 percent, which is equal to 4.35 percent.
The mass-mass percent composition formula is only one of many methods used to express the mass percentages of solutes and solvents that make up a solution. Some others are molarity mole fraction and molality. However, these other formulas involve using other known quantities like moles and volume.