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 n_A and n_B respectively: then the mole fractions of A and B are given as:

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

= n_A / n_A + n_B

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