Mole Fraction Calculator
Find the mole fraction of each component in a mixture. Add a row for every substance and enter its moles, and the calculator returns each mole fraction and the total moles. The fractions always sum to 1.
How to calculate mole fraction
- Add a row for each component in the mixture.
- Enter the number of moles of each component.
- Read each mole fraction, the moles of that component divided by the total moles.
Examples
Two components
A = 2 mol, B = 3 mol
x(A) = 0.4, x(B) = 0.6
Single component
X = 4 mol
x(X) = 1
Frequently asked questions
What is mole fraction?
Mole fraction is the moles of one component divided by the total moles of all components in a mixture. It is a unitless number between 0 and 1.
What is the mole fraction formula?
The mole fraction of component i equals the moles of i divided by the sum of the moles of every component, x_i = n_i / n_total.
Do mole fractions add up to 1?
Yes. Because each fraction is a share of the same total, the mole fractions of all components in a mixture always sum to exactly 1.
How do I get moles from a mass?
Divide each mass in grams by that substance's molar mass in grams per mole, then enter the resulting moles for each component.
How is mole fraction different from mass percent?
Mole fraction counts particles using moles, while mass percent compares masses. The two differ whenever the components have different molar masses.
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