Synonym: Mole fraction = Molar fraction

x_k = \frac{\nu_k}{\sum_i \nu_i} = \frac{N_k}{\sum_i N_i}

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