Concentration of Solutions
Percent by Mass
Percent by mass, or %(m/m) of solution, refers to the mass of solute dissolved in 100 g solution. It has no unit because it is a ratio of mass expressed in grams.
\[
\begin{aligned}
\%\,(\,\tfrac{\text{mass}}{\text{mass}}\,)
&= \frac{\text{mass of solute}}{\text{mass of solution}} \times 100
\end{aligned}
\]
The mass of solution is obtained by adding the mass of solute and the mass of solvent. The equation is expressed this way:
mass of solution = mass of solute + mass of solvent
