The change in entropy ($\Delta S$) during a phase transition at a constant temperature is given by the formula $\Delta S = \frac{Q}{T}$ [1], where $Q$ is the heat absorbed and $T$ is the absolute temperature. Given: Mass of ice, $m = 1\text{ kg} = 1000\text{ g}$ Latent heat of fusion of ice, $L = 80\text{ cal/g}$ Absolute temperature, $T = 0^{\circ}\text{C} = 273\text{ K}$ The total heat absorbed to melt the ice is $Q = m \times L = 1000\text{ g} \times 80\text{ cal/g} = 80000\text{ cal}$. Now, calculating the change in entropy: $\Delta S = \frac{80000\text{ cal}}{273\text{ K}} \approx 293\text{ cal/K}$.