Answer to Question #231417 in Chemical Engineering for pavani

Question

21.What are the different concentration scales to measure air pollutants in the atmosphere?

Answer 1

Concentrations are most commonly expressed as mass per unit volume (e.g micrograms per cubic meter, gram per cubic liter, etc)$.$

However, for gases, volume percent, mole percent and parts per can be used also i.e 1 volume percent = 10,000 ppmv (i.e., parts per million by volume) with a million being defined as 10⁶.