Question

An ice cube at 0 degrees Celsius melts when placed inside a room at 22 degrees Celsius. Based on the concepts of enthalpy, entropy, and Gibbs free energy, which of the following best explains why the process is thermodynamically favorable?

A. Melting ice releases energy (ΔH<0), and ΔS<0 because the motion of the H₂O molecules decreases as it transitions from solid to liquid. At a temperature higher than 0 degrees Celsius, the term TΔS is smaller than ΔH, resulting in a thermodynamically favorable process with ΔG<0.
B. Melting ice releases energy (ΔH<0), and ΔS>0 because the motion of the H₂O molecules increases as it transitions from solid to liquid. At a temperature higher than 0 degrees Celsius, the term TΔS is greater than ΔH, resulting in a thermodynamically favorable process with ΔG>0.
C. Melting ice requires energy (ΔH>0), and ΔS<0 because the motion of the H₂O molecules decreases as it transitions from solid to liquid. At a temperature higher than 0 degrees Celsius, the term TΔS is smaller than ΔH, resulting in a thermodynamically favorable process with ΔG>0.
D. Melting ice requires energy (ΔH>0), and ΔS>0 because the motion of the H₂O molecules increases as it transitions from solid to liquid. At a temperature higher than 0 degrees Celsius, the term TΔS is greater than ΔH, resulting in a thermodynamically favorable process with ΔG<0.

Answer 1

The correct explanation is option A. Melting ice releases energy (ΔH<0), and ΔS<0 because the motion of the H₂O molecules decreases as it transitions from solid to liquid.

Step-by-step explanation:

The correct answer is option A. Melting ice releases energy (ΔH<0), and ΔS<0 because the motion of the H₂O molecules decreases as it transitions from solid to liquid. At a temperature higher than 0 degrees Celsius, the term TΔS is smaller than ΔH, resulting in a thermodynamically favorable process with ΔG<0.

Enthalpy (ΔH) is the heat energy absorbed or released during a process, and entropy (ΔS) is a measure of the disorder or randomness of a system. Gibbs free energy (ΔG) represents the balance between enthalpy and entropy in a system.

In this case, melting ice is an exothermic process, meaning it releases energy (ΔH<0). The transition from solid to liquid results in a decrease in the motion of the H₂O molecules, leading to a decrease in entropy (ΔS<0).

However, at a temperature higher than 0 degrees Celsius, the term TΔS (where T is temperature) is smaller than ΔH. This means that the increase in enthalpy is greater than the decrease in entropy, resulting in a negative value for Gibbs free energy (ΔG<0). A negative value for ΔG indicates that the process is thermodynamically favorable.