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What Is Mole Fraction?

The unit of concentration in chemistry is mole fraction, which has been determined to be equal to a component's number of moles divided by the total number of moles in a solution.

The Mole fraction is a dimensionless term, as it represents a ratio between two values. When put together, the mole fraction of all solution components equals 1.

It is significant to determine mole fraction when combining two reactive components, as the two components ratio is known if the mole fraction of each of them is known.

Moreover, mole fraction multiplying by 100 provides just mole percent, which is the same as a mole fraction but in a different perspective.

Different concentrations, including molarity, molality and mass-percent composition, can yield mole fractions. Moreover, in the production of phase charts, the mole fraction is utilized so often.

Also it does not, in comparison with the molar concentration, rely on temperature and does not need knowledge of the phase densities involved.

By weighing the proper masses of the elements a mixture of known mole fractions can be produced.

For the mole fractions x=0.1 and x=0.9 the measurement is symmetric and the 'solvent' and 'solute' roles are reversible.

Furthermore, the mole fraction can be stated in the mixture of ideal gases as a ratio of partial pressure with full mixed pressure.

What is Mass Fraction?

The ratio of the mass of the substance to the overall mass of the mixture is the mass fraction of a substance.

It is also known in percentage terms as percentage by mass or mass percent. As the mass fraction is a mass-to-mass ratio, the quantity is without any dimension.

A substance's mass fraction being an intensive quantity is irrespective of the pressure, the temperature and the place of the material.

Unless a chemical change or a net physical transmission of any substance is observed it stays constant.

Thus, the mass percentages of a substance will be consistent everywhere around the world.

Furthermore, we call the mass fractions as the weight fractions as well. However, the symbol m/m is presented as a mass fraction and the symbol w/w is assigned to weight fraction.

In the same manner mass percentage is often referred to as weight percentage. And the symbol m/m% is used to represent percent by mass while the sign w/w% is used to represent percent by weight.

Difference Between Mole Fraction and Mass Fraction?

The chemical compound comprises the solvent and the solute and forms the chemical mixture in a chemical analysis.

However, the terminologies used to express the ratios among various compound’s components are the mole fraction and mass fraction.

Although both the fractions are quite similar and represent the ratios among the compound’s components yet they aren’t the same quantities or terms.

However, there lies an important link among mole fraction and mass fraction in a chemical mixture.

The ratio of the solute mass to the overall mixture mass is known as the mass fraction.

Though, the mole fraction deals with the moles of various component parts of a compound, whereas mass fraction deals with the masses of distinct components of a compound and this explains the main difference between both the quantities.

Furthermore, the mole fraction and mass fraction could be interconverted into each other of the same compound.

Can Mole Fraction Be More Than 1?

Another measure of concentration in chemistry is the mole fraction of a chemical compound.

As we learned above, mole fraction is simply the number of moles relative to the total number of moles of that specific substance.

The mole fraction of a substance is always ranging from 0 and 1 since it can never exceed the entire number of moles in a mixture.

And thus it can never be more than 1. Generally, the mole fraction is expressed as using the sign X however, for a substance

i the mole fraction is defined as


where the total number of moles in the mixture is ntotal

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