AIIMS 2018 Chemistry Colligative Properties MCQ Question

The Van 't Hoff factor, $i$, represents the degree of dissociation of a solute in a solvent, influencing colligative properties like freezing point depression. In the case of ionic compounds, $i$ can be expressed as $i = 1 + \alpha(n - 1)$, where $\alpha$ is the degree of dissociation and $n$ is the number of particles the solute dissociates into. Option C correctly reflects this relationship, indicating that as $\alpha$ increases, $i$ increases proportionally based on the number of dissociated particles.

Options A and B incorrectly suggest that the relationship is additive or subtractive in a way that does not accurately represent the dissociation process, while option D fails to account for the contribution of the original solute particle, leading to an incomplete understanding of the factor's calculation.