Mole Fraction Calculator

Calculate mole fraction (χ) for a two-component mixture. Mole fractions always sum to 1.

mol
mol

MOLE FRACTION OF A

0.4 χA

χ OF B

0.6

TOTAL MOLES

5

FORMULA

χ = nᵢ / n_total

💡 How to Calculate Mole Fraction

What Is Mole Fraction?

Mole fraction (χ) is a dimensionless measure of concentration that expresses the ratio of the number of moles of one component to the total number of moles in a mixture. Mole fractions are used in Raoult's Law (vapor pressure), Dalton's Law (partial pressures of gases), and colligative property calculations.

How to Calculate Mole Fraction

Mole Fraction Formula

χᵢ = nᵢ / n_total

Where:

  • χᵢ = mole fraction of component i
  • nᵢ = moles of component i
  • n_total = total moles of all components

A key property of mole fractions is that they always sum to 1: χ₁ + χ₂ + ... = 1. You can find the number of moles from grams using molar mass, then calculate mole fractions. This is also related to molality and molarity.

🔗 Related Calculators

Molarity CalculatorCalculate molarity (M = mol/L) — the most common concentration unit in chemistry. Includes dilution formula M₁V₁ = M₂V₂.Molality CalculatorCalculate molality (mol solute / kg solvent). Temperature-independent concentration unit for colligative properties.Mole CalculatorUniversal mole converter — convert between grams, atoms/molecules, and liters (at STP). The central concept of chemistry.