Explanation:

Why is ice at 273 K more effective in cooling than water at the same temperature? Solution : Cooling takes place when heat is removed from a system. In case of ice at 0oC, it will first take heat (latent heat) from the medium to convert itself into water at 0oC and then into water at higher temperature. In short, in case of ice at 0oC, there will be change in phase so more energy will be required, whereas in case of water at 0oC, there will be no change in phase. Hence, lesser energy will be taken from the surroundings. So, at same temperature of 273 K, large amount of heat will be removed by ice from the surroundings than in case of water. Hence, ice at 273 K is more effective in cooling than water at the same temperature.