To account for all abnormal cases (i.e., those of association or dissociation of solute molecules when dissolved in a solvent), van’t Hoff introduced a factor, i, known as van’t Hoff factor.
$\mathrm{i}=\frac{\text{ Number of particles after association or dissociation }}{\text{ Number of normal solute particles }}$
The ratio of van’t Hoff factor (i) to the number of ions furnished by one molecule of solute is known as osmotic coefficient ‘g’
$\text{ i.e., }\mathrm{g}=\frac{\mathrm{i}}{\mathrm{n}}=\frac{{\mathrm{van}}^{\mathrm{\prime }}\mathrm{t}\text{ Hoff factor }}{\mathrm{n}}$
Consider 0.5% aqueous solution of potassium chloride which was found to freeze at 272.76 K. [Given K_f of water = 1.86 K kg mol^-1) and answer the following questions.