Mole Fraction Calculator
Works out each component’s share of a mixture by moles.
Mole fraction of A
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Total moles — mol
All components
The formula
x = moles of the component ÷ total moles
The fractions of all components add up to 1, and mole fraction has no units.
What to watch out for
Leave unused components at zero. In a gas mixture, mole fraction also gives each gas’s share of the total pressure.
Frequently Asked Questions
What is the mole fraction of 1 mol in 4 mol total?
0.25, or 25 mole percent.
What is the difference between mole fraction and mass fraction?
Mole fraction counts particles and mass fraction weighs them, so a heavy component has a larger mass fraction than mole fraction.