In chemistry and physics, the dimensionless mixing ratio is the abundance of one component of a mixture relative to that of all other components. The term can refer either to mole ratio or mass ratio.
In atmospheric chemistry and meteorology
In meteorology, mixing ratio usually refers to the mass ratio ζi, which is defined as the mass of a constituent mi divided by the total mass of all other constituents in a mixture:
The mass ratio of water vapor in air can be used to describe humidity.
Mixtures/solutions mixing ratio
Two binary solutions of different compositions can be mixed with various mixing ratios by masses, moles, or volumes.
The mass fraction of the resulting solution from mixing solutions with mass fractions w1 and w1 is given by:
or, by substituting the densities and considering equal volumes of different concentrations
The formula can be extended to more than 2 solutions to be mixed giving:
- IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "mixing ratio".
- "Pure and Applied Chemistry, 2008, Volume 80, No. 2, pp. 233-276". Iupac.org. 2016-06-14. Retrieved 2016-06-30.