Synonym: Mole fraction = Molar fraction

x_i = \frac{\nu_i}{\nu} = \frac{N_i}{N}

where

	amount of substance of the -th mixture component
	total amount of substance in the mixture
	Avogadro constant
	amount of molecules/atoms in the -th mixture component
	total amount of molecules/atoms in the mixture

As per definition the sum of all mole fractions is strictly unit: .

See Also