Mole fraction
In chemistry, the mole fraction or molar fraction (![x_i](/Images/godic/202501/27/05e42209d67fe1eb15a055e9d3b3770e2830.png")
) is defined as the amount of a constituent (expressed in moles), ![n_i](/Images/godic/202501/27/f75ef7544498f247df440d828aee41aa2830.png")
, divided by the total amount of all constituents in a mixture, ![n_{tot}](/Images/godic/202501/27/9fc309b1b2871dd5f0ee4cace36aadfc2830.png")
:
The sum of all the mole fractions is equal to 1:
The same concept expressed with a denominator of 100 is the mole percent or molar percentage or molar proportion (mol%).