Question

When water freezes to form ice, which one of the following statements is true?

A. The temperature decreases during freezing as energy is lost

B. There is no energy lost by the water as it freezes, because the temperature does not change

C. Energy is lost by the water as it freezes, but the temperature does not change

Answer 1

During freezing of water to form ice, temperature remains constant ( usually 0 C or 32 F). However, energy is released to the surroundings and energy is lost.

When we placed a glass of water inside freezer, water releases heat energy to the surroundings and its temperature decreases. However, in liquid state the velocity of water molecule is higher and when water release energy, the molecules lose their kinetic energy and get closer to each other and finally form hydrogen bond to become ice. So, freezing of water is exothermic process during which system loses energy.

So correct option is (c).