Question

Unit of mole fraction is
A.Moles/litre
B.Moles/litre
C.Moles-litre
D.Dimensionless

Answer 1

Hint: First, we need to know what mole fraction is. The number of molecules of a specific component in a mixture divided by the total number of moles in the mixture is known as the mole fraction. It's a means of expressing a solution's concentration. In other terms, it is the total amount of all constituents in a combination divided by the amount of a constituent (given in moles). The amount fraction is another name for the mole fraction.

Complete answer:
X can be used to express the molar fraction. The mole fraction is, if the solution consists of components A and B
\[Mole Fraction Of Solute\]=\[\dfrac{{{\text{Moles Of Solute}}}}{{{\text{Moles Of Solute + moles of solvent}}}}\]
\[ = \dfrac{{{n_a}}}{{{n_a} + {n_b}}}\]
Thus, a mole fraction is defined as the number of moles of a component divided by the total number of moles in a solution. Mole fraction is a unitless phrase because it represents a ratio.
Hence, the correct option is d) which is dimensionless.
Option a) and option b) is false because mole/litre is a unit of molarity and mole fraction has no unit.
Similarly, the ratio of moles to moles cannot be Moles-litre. Thus, option c) cannot be the
answer.

Hence, the correct option is d) which is dimensionless.

Note:
We must be noted that the total mole fraction of all components is always one. The mole fraction represents a fraction of molecules, and the mass fraction is different from the mole fraction since different molecules have different masses. The mole percent, molar percentage, or molar proportion is the same notion represented with a denominator of 100. Mole fraction is used very frequently in the construction of phase diagrams.