Question

The sum of mole fraction of all components of a solution is unity.

• A. True
• B. False

Answer 1

The correct option is A True

Mole fraction is the number of moles of part over total moles OR

$Molefraction=\frac{\text{Number of moles of a solute}}{\text{Total number of moles in solution}}$

If for example, we take that number of moles of solute as $n_1$ and that of solvent is $n_2$

Then, Mole fraction of solute $=\frac{n_1}{n_1+n_2}$

Mole fraction of solvent $=\frac{n_2}{n_1+n_2}$

Then, sum of mole fractions will be $=\frac{n_1}{n_1+n_2}+\frac{n_2}{n_1+n_2}=1$