Formula Related to The Mole Fraction

In chemistry, the mole fraction gets calculated for any solution. The mole fraction is the ratio of the amount of a molecule of any particular particle to the amount of molecule of all the particles.

In other words, when you calculate the amount of any particular particle in any given solution, then the fraction of that calculation is known as the mole fraction.

Ideally, this can be expressed as 

Xi = Ni / Ntot

Where Xi = The mole fraction.

Ni = The amount of molecules of a particular particle.

Ntot = Total amount of molecules of the solution.

Definition of Mole fraction

The mole fraction or molar fraction can be defined as a unit of moles of any particular item divided by the total number of moles present in the solution or the mixture.

As per the mole fraction definition, the total number of moles present in the solution or the mixture will always be 1, so it will not always be 1. So, naturally, the fraction will always be less than 1.

Formula Of Mole Fraction

If there are only two different substances in any solution or mixture, then the mole fraction of the solute will be moles of solute divided by the mole of solute + the mole number of solvent.

And for the mole fraction of solvent, it will be moles of solvent divided by the mole of solute + the mole of solvent.

This formula helps determine the fraction of each substance in any mixture or solution. This even helps to determine the percentage of every different substance in any given solution or mixture.

During analyzing any solution, you need to measure the concentration of the components in moles. Then you have to calculate the mole fraction of the solute and the mole fraction of the solvent differently by calculating the mole of the solute or the solvent divided by the addition of those types.

The mole fraction is a ratio. So, the number is dimensionless, and along with that, it is unitless. Therefore, the fraction is always less than one.

How To Find Out the Mole Fraction of a Solution or Mixture with Multiple Particles or multiple Solutes

This is the expanded version of the mole fraction formula. To find the mole fraction of any particular solute or particle, you need to find the mole number of every different solute or particle.

Now, divide the mole number of the particular solute or particle with the sum of all the particles or solutes and the solvent.

The formula looks like 

Mole Fraction (Xsolute) = Mole number of the solute / (Mole number of solute1 + Mole number of solute2 + ……. + Mole number of soluten + Mole number of solvent)

Here, n is the total number of solutes present in the solution. With the help of this formula, you will be able to calculate and find the mole number with any number of solutes in a solution or a mixture.

Advantages of the Mole Fraction

Mole fraction has some unique properties. This has some advantages, which need to get discussed.

• The mole fraction is not temperature-dependent at all. The temperature can’t change the mole fraction of any solute.
• This measurement is symmetric. If one of them is 0.2, the other will be 0.8. As the total will always be1
• Molality can easily be derived from the molar fraction of any solutes in any given solution.
• For ideal gases, the mole fraction is the volume fraction.

Limitations Of the Mole Fractions

• For gases, the mole fraction can be changed by the gas’s partial pressure.
• Mass fraction can’t get determined through this theory.
• For gaseous mixture, volume can affect this phenomenon and calculation.

Mole percentage

Multiplying the mole fraction with 100 can give you a mole percentage. This is also known as amount/amount per cent. So, here mole per cent can also be maximum up to 100 and revert to the mole fraction dividing by 100.

Conclusion

The formula of mole fraction can help to know the fraction of different solutes or substances in any given solution or mixture. This is not a temperature or concentration-related phenomenon like molar conductivity. It can also help you find out the fraction of any substance from a solution or mixture of n number of substances or solutes.

The total of the molar fraction will always be 1. This can’t be more or less. And so how, the mole fraction of other substances will be less than 1. For a solution of one solute and one solvent, if the molar fraction of the solute is 0.3, the same solvent will be 0.7.