Mole Fractions

Solution composition can also be described by the number of moles of solute and solvent. The mole fraction of a solution component, then, is the ratio of the number of moles of that component divided by the total number of moles. We could multiply a mole fraction by 100% and speak of mole %, but we usually avoid this usage to avoid confusion with mass %. Thus if a solution is described in terms of %. composition, you can assume mass %.