Question

Define the following terms:

(a) Mole fraction (x)
(b) Molality of a solution (m)

Answer 1

(a) Mole fraction (x):

The mole fraction of a component is the ratio of the number of moles of the component to the total number of moles of all the components present in the solution.

(b) Molality of solution (m):

Molality is defined as the number of moles of the solute per kilogram of the solvent. It is represented by m.

\(= \frac{\text{Number of moles of the component}}{\text{Total number of moles of all the components}}\)

For a binary solution, mole fraction of component A,

x_A = n_A / n_A+n_B

Similarly, for B, χ_B = n_B / n_A+n_B

and x_A + x_B = 1