Question

when water cools from 10°c and then freezes to become ice, which of the following best describes the heat flow between the system and surroundings? answer: a the energy of the universe is decng because the water is cold. b the energy of the universe is increasing because the energy had to be removed from the water c the water is absorbing energy as its temperature decreases, and that energy was released by the surroundings. d the water is releasing energy as its temperature decreases, and that energy is absorbed by the surroundings.

Explanation:

When water cools and freezes, it is an exothermic process. In an exothermic process, the system (water) releases energy. This released energy is absorbed by the surroundings. The first law of thermodynamics states that the energy of the universe is constant. Options A and B are incorrect as they wrongly state a change in the energy of the universe. Option C is incorrect as it says the water is absorbing energy (which would be endothermic, but cooling and freezing is exothermic).

Answer:

D. The water is releasing energy as its temperature decreases, and that energy is absorbed by the surroundings.