Mole fraction is a unit of concentration, defined to be equal to the number of moles of a component divided by the total number of moles of a solution.

Because it is a ratio, mole fraction is a unitless expression.

**Formula to calculate mole fraction.**

X is the component that is being identified for mole fraction.

**Example:**

Calculate the mole fraction of carbon tetrachloride (CCl_{4}) in solution if 2.5 moles of CCl_{4} is dissolved in 8.0 moles of benzene (C_{6}H_{6}).

Thus, the mole fraction is 0.24.