The scientist us Ppm to measure instead of percentage in some cases .
Step-by-step explanation:
Concentration of solution
It is the amount of solute present in given amount of solution .
There are different methods to know about the concentration of solutions .
out of it mass or volume percentage and parts per million is one of the methods .
Mass Percentage
it is calculated by taking the ration of mass of solute to mass of solution x 100.
That is:
Mass percentage = mass of solute/mass of solution x 100
Parts per million (ppm )
It is calculated by taking the ratio of number of parts of solute /number of parts of solution x 10⁶.
This method is preferred only when concentration of solute is very less like used in case to measure amount of pollutants in air .It is an efficient method than percentage method in that case .