It is defined as:
Mole fraction of a component =
Number of moles of the component
Total number of moles of all the components
(1 4)
For example, in a binary mixture, if the number of moles of A and B are
nA and nB respectively, the mole fraction of A will be
xA =

A
A
B
 
n
n
n
(1 5)
For a solution containing i number of components, we have:
xi = 



i
1
2
i n
n
n
n  = 
i
i
n
n
(1