Question

Explain mole fraction by an example.

Hint:

Mole fraction is a unitless quantity and always sums up to 1 for all components in a mixture.

Answer 1

Step 1: Definition of Mole Fraction Mole fraction (\(X\)) of a component in a mixture is the ratio of the number of moles of that component to the total number of moles in the mixture. \[ X_A = \frac{\text{moles of component A}}{\text{total moles in the solution}} \] Step 2: Example Consider a solution containing 2 moles of ethanol (\(C_2H_5OH\)) and 3 moles of water (\(H_2O\)). \[ X_{\text{ethanol}} = \frac{2}{2+3} = \frac{2}{5} = 0.4, \quad X_{\text{water}} = \frac{3}{5} = 0.6 \]