What is mole fraction ? Explain in brief.

Explanation

Definition : The ration between mole of one component of solution and total moles of solution is known as mole fraction of component.
Commonly used symbol for mole fraction is x and subscript used on the right hand side of x denotes the component.
Mole fraction of a component `= ("Number of moles of the component")/("Total number of moles of all the components")`
For example, in a binary mixture, if the number of moles of A and B are `n_(A)` and `n_(B)` respectively, the mole fraction of A will be
`x_(A)=(n_(A))/(n_(A)=n_(B))`
For a solution containing .i. number of components, we have :
`x_(i)=(n_(i))/(n_(1)+n_(2))+.....+n_(i)=(n_(i))/(Sigma n_(i))`
It can be shown that in a given solution sum of all the mole fractions is unity, i.e.,
`x_(1)+x_(2)+ ............. +x_(i)=1`
Mole fraction unit is very useful in relating some physical properties of solutions, say vapour pressure with the concentration of the solution and quite useful in describing the calculations involving gas mixtures.