\begin{align*} \text{Given:} & \\ \text{Molality of } K_2SO_4 \text{ solution} &= m = 0.1 \text{ m} \\ \text{Freezing point of solution} &= T_f = -4.3^\circ \text{C} \\ K_f \text{ of water} &= 1.86 \text{ K kg mol}^{-1} \\ \\ \text{To find:} & \text{ van’t Hoff factor} \\ \\ \text{Formula:} & \quad \Delta T_f = i \cdot K_f \cdot m \\ \\ \text{Calculation:} & \\ \Delta T_f &= T_f^0 – T_f \\ &= 0^\circ \text{C} – (-4.3^\circ \text{C}) = 4.3 \text{ K} \\ \\ \text{Now, using formula,} & \\ \Delta T_f &= i \cdot K_f \cdot m \\ \therefore i &= \frac{\Delta T_f}{K_f \cdot m} \\ &= \frac{4.3 \text{ K}}{1.86 \text{ K kg mol}^{-1} \cdot 0.1 \text{ mol kg}^{-1}} \\ &= 2.311 \\ \\ \text{The value of van’t Hoff factor is} & 2.311. \end{align*}