Question

Knowing that the second law of thermodynamics states that everything tends to entropy, why does water and other volatile substances spontaneously evaporate, getting energy to do so from the surface they were touching? Wouldn't that unobey said law, as the substance would get more energetic and the surface it was previously touching less energetic, decreasing the entropy?

Answer 1

The second law of thermodynamics states that the total entropy of a system either increases or remains constant in any spontaneous process. When water or other volatile substances evaporate, they gain energy from the surface they were touching, resulting in an overall increase in entropy for the system.

Step-by-step explanation:

The second law of thermodynamics states that the total entropy of a system either increases or remains constant in any spontaneous process; it never decreases. This means that heat transfer occurs from higher- to lower-temperature objects, increasing the entropy of the system.

When water or other volatile substances evaporate, they gain energy from the surface they were touching, which increases their entropy. As the substance gains energy, its molecules gain enough kinetic energy to overcome attractive forces and break away from each other, resulting in a phase change from liquid to gas. This increase in entropy outweighs any decrease in entropy at the surface, resulting in an overall increase in entropy for the system.