Parts per million
Mole fraction
Parts per million
o
Parts per million can be defined as the ratio of number of parts of the component to the total number of parts of all components of the solution multiplied by 10 6 .
o It is denoted by ppm . o
It is used to express concentration of a solution where solute is present in trace For instance , concentration of pollutants in water or atmosphere is expressed in terms of g mL – 1 or ppm .
o Mathematically ,
o
For example , let 0.0005g of NaCl be dissolved in 100mL of water
then parts per million =
Mole fraction
o
Mole fraction can be defined as the ratio of number of moles of the component in the solution to the total number of moles of all components in the solution .