Parts Per Million ($$\text{ppm}$$)

$$\text{ppm} = \frac{\text{Mass of Solute}}{\text{Total Mass of Solution}} \times 10^6$$

Concept: Expresses concentration when a solute is present in trace quantities (e.g., pollutants in water or air).

Notation:

• $$\text{ppm}$$ = Parts per million (dimensionless ratio scaled by $$10^6$$)