# Mole fraction

## Description

In chemistry, the mole fraction is defined as the amount of a constituent divided by the total amount of all constituents in a mixture.The mole fraction is also called the amount fraction. It is identical to the number fraction, which is defined as the number of molecules of a constituent divided by the total number of all molecules . It is one way of expressing the composition of a mixture with a dimensionless quantity (mass fraction is another).

Related formulas## Variables

χ | mole fraction (dimensionless) |

n_{i} | amount of a constituent (dimensionless) |

n_{tot} | total amount of all constituents (dimensionless) |