Question

Why is ice at 273K more effective in cooling than water at the same temperature?

Answer 1

Hint: To answer this question, you must recall the concept of latent heat. Water converts from ice to water absorbing heat. So, more energy is stored in ice than in water at the same temperature.

Complete step by step answer:
- The heat that is required to convert one state of a substance to the other without the change in temperature is known as latent heat. In other words, it is the energy required to convert a substance from solid state to liquid state or from liquid state to vapour state keeping the temperature constant.
- The heat required to convert a substance in solid phase to liquid at constant temperature and pressure is known as latent heat of fusion. Similarly, the heat required to convert a substance in liquid phase to vapours at constant temperature and pressure is known as latent heat of vaporization.
- At 273 K, ice absorbs more heat than water from the substance to overcome the latent heat of fusion and thus providing a more effective cooling effect. Water however does not absorb any extra heat from the substance.

Thus, ice is more effective in cooling than water at 273 Kelvin.

Note:
When a substance absorbs heat from its surroundings, due to the loss of the heat in the surroundings, a cooling effect is observed. Not only melting of ice, but evaporation causes cooling as well. It is the process of conversion of a liquid to vapour at room temperature. It is different from vaporization as it occurs at room temperature while the latter occurs at the boiling point. When evaporating, the liquid absorbs heat from its surroundings thus causing a cooling effect.