Mole Fraction Calculator
Calculate mole fraction, mole percentage, and analyze solution composition for mixtures and gases
Calculate Mole Fraction
Number of moles of the substance of interest
Number of moles of the solvent (or sum of other components)
Calculation Results
Calculation Details
Formula: χ = n_solute / (n_solute + n_solvent)
Calculation: χ = 0 / (0 + 0) = 0.0000
Mole Percentage: χ × 100% = 0.00%
Component analysis:
Composition Analysis
Example Calculation
Ethanol-Water Solution Example
Problem: What is the mole fraction of ethanol in a solution containing 2.5 moles of ethanol and 10.0 moles of water?
Given: Ethanol (solute) = 2.5 mol, Water (solvent) = 10.0 mol
Method: Use Method 1 (Solute + Solvent)
Step-by-Step Solution
Step 1: Apply formula: χ_ethanol = n_ethanol / (n_ethanol + n_water)
Step 2: Calculate total moles: n_total = 2.5 + 10.0 = 12.5 mol
Step 3: Calculate mole fraction: χ_ethanol = 2.5 / 12.5 = 0.2000
Step 4: Convert to percentage: 0.2000 × 100% = 20.00%
Answer: Ethanol mole fraction = 0.2000 (20.00%), classified as significant component
Mole Fraction Scale
Key Formulas
Method 1: Solute + Solvent
χ = n_s / (n_s + n_solv)
Best for single solute solutions
Method 2: Solute / Total
χ = n_s / n_total
Best for multiple solute solutions
Gas Method
χ = P_partial / P_total
For gas mixtures using Dalton's law
Mole Percentage
mol% = χ × 100%
Convert fraction to percentage
Common Examples
Understanding Mole Fraction
What is Mole Fraction?
Mole fraction (χ) is a dimensionless concentration unit that represents the ratio of moles of a particular component to the total moles in a mixture. It provides a measure of the proportion of each substance in the solution.
Why is it Important?
- •Temperature-independent concentration unit
- •Essential for colligative property calculations
- •Used in Raoult's law and vapor pressure calculations
- •Important for gas mixture analysis using Dalton's law
Properties of Mole Fraction
Dimensionless
No units - pure ratio
Always between 0 and 1
Sum Equals Unity
Σχᵢ = 1.0000
All fractions in mixture sum to 1
Temperature Independent
Does not change with temperature
Unlike molarity or molality