Chemistry Formula
Mole Fraction Formula
Finds a component's fraction of the total amount in a mixture.
Formula Summary
Mole Fraction
Finds a component's fraction of the total amount in a mixture.
- Category
- Chemistry
- Equation
- Xᵢ = nᵢ ÷ nₜₒₜₐₗ
- Calculator
- Use Mole Fraction Calculator →
Equation
Xᵢ = nᵢ ÷ nₜₒₜₐₗ
Variables
- Xᵢ = mole fraction
- nᵢ = component moles
- nₜₒₜₐₗ = total moles
How to Use This Formula
- Identify the known values from the problem statement.
- Convert all values into compatible units.
- Substitute the values into the equation and calculate the result.
- Check that the final answer has the correct unit and meaning.
Explanation
Mole fraction represents the ratio of the number of moles of one component to the total number of moles in a mixture. It describes the relative amount of each substance present.
Worked Example
A mixture containing 2 moles of oxygen and 8 total moles has an oxygen mole fraction of 2 ÷ 8 = 0.25.
Common Mistakes
- Using mass instead of moles.
- Forgetting to include all components in total moles.
- Confusing mole fraction with molarity.
Applications
- Analyzing gas mixtures.
- Solution composition calculations.
- Chemical mixture analysis.
Related Formulas
Ideal Gas Law
PV = nRT
Relates pressure, volume, amount, and temperature of an ideal gas.
Learn formula →