What is the Difference Between Mole Fraction and Mass Fraction?

Mole fraction and mass fraction are both used to express the relative fractions of different constituents in a mixture. They are unitless quantities, as the ratios have the same unit, and thus the units cancel out. However, there are key differences between the two:

• Mole Fraction: This is the ratio between the moles of a constituent and the sum of moles of all constituents in the mixture. Mole fraction is calculated using moles of constituents and is often used in the construction of phase diagrams.
• Mass Fraction: This is the ratio between the mass of a constituent and the total mass of the mixture. Mass fraction is calculated using masses of constituents and is more commonly used in everyday applications and measurements.

In summary:

• Mole fraction deals with the ratios of amounts in units of moles.
• Mass fraction deals with the ratios of masses.

Mole fraction can be converted into the mass fraction of the same compound and vice versa.

Comparative Table: Mole Fraction vs Mass Fraction

Here is a table comparing mole fraction and mass fraction:

Mole fraction and mass fraction are both used to express the relative fractions of different constituents in a mixture, but they differ in the way they are calculated and whether they are unitless or not.