Select the correct expression for the "parts per million" concentration term:

$\text{ppm} =\frac{\text{Number of parts of the component}}{\text{Total number of parts of all components of the solution}}×10^6$

The correct answer is Option (1)  →  $\text{ppm} =\frac{\text{Number of parts of the component}}{\text{Total number of parts of all components of the solution}}×10^6$

• "Parts per million (ppm)" expresses very dilute concentrations.
• It is defined as the ratio of the mass (or moles) of solute to the total mass (or volume) of solution multiplied by 10⁶.

 Hence, the correct option is:
ppm = (Number of parts of the component / Total number of parts of all components of the solution) × 10⁶