ETS Major Field Test Chemistry Practice Test

In a spontaneous process such as water freezing, the freezer plays a crucial role by directing heat away from the water. This process causes the water molecules to lose energy and transition from a liquid state to a solid state (ice). As heat is removed from the water, the temperature drops, allowing the molecules to slow down and become more ordered, which reflects a decrease in the entropy of the water itself.

However, the act of removing heat from the water increases the entropy of the surroundings. The energy extracted from the water increases the disorder in the environment of the freezer, effectively allowing for the spontaneous process of freezing to occur. This highlights the relationship between system entropy (in this case, the water) and the surroundings: while the entropy of the water decreases as it freezes, the overall entropy of the universe—including both the water and the surroundings—tends to increase, in line with the second law of thermodynamics.