How to calculate Mole Fraction?

Mole Fraction is the ratio of number of moles of a particular component to the total number of moles of the solution. If a substance ‘A’ dissolves in substance ‘B’ and their number of moles are nA and nB respectively: then the mole fractions of A and B are given as:

Mole fraction = Number of Moles / Total No. of mole,

= nA / nA + nB

Example: What is the mole fraction of carbon tetrachloride (CCl4) in solution if 3.47 moles of CCl4 is dissolved in 8.54 moles of benzene (C6 H6)?

Mole fraction CCl4 = Moles of CCl4 / Total Moles

= [3.47 moles CCl4 / (3.47 moles CCl4 x 8.54 moles of C6 H6)]

= 0.289