- Mass fraction (chemistry)
The sum of all the mass fractions is equal to 1:
It is one way of expressing the composition of a mixture in a dimensionless size (mole fraction is another).
For elemental analysis, mass fraction (or "mass percent composition") can also refer to the fraction of the mass of one element to the total mass of a compound. It can be calculated for any compound using its empirical formula or its chemical formula.
The relation to molar concentration is like that from above substituting the relation between mass and molar concentration.
Multiplying mass fraction by 100 gives the mass percentage, sometimes referred to by the obsolete term weight-weight percentage or weight percent (abbreviated as w/w% or wt%).
The mole fraction xi can be calculated using the formula
where Mi is the molar mass of the component i and M is the average molar mass of the mixture.
Articles related to solutions Solution Concentration
and related quantities
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