Question

During the phase change, when water freezes, its converted to ice in which molecules is in more structured order. Why doesn't this contradict the Second Law of Thermodynamics?

• A. Because the density of the water is decreasing
• B. Because the water is gaining entropy as it goes from liquid to solid state
• C. Because the water's internal energy is decreasing
• D. Because the surroundings are losing entropy
• E. Because the surroundings are gaining entropy

Answer 1

Answer: (E)

Because the surroundings are gaining entropy

The heat energy released during the freezing of water goes to the surrounding which increases the entropy of the surrounding. Thus although the entropy of the water decreases, the entropy of the surrounding increases such that the net entropy of system (water) and surrounding is greater than zero which does not violate the Second Law.

Hence option E is correct.