Entropy and Second Law of Thermodynamics

Entropy and Second Law of Thermodynamics

For an isolated system, the change in energy remains constant. Therefore, an increase in entropy in such systems is the natural direction of a spontaneous change. This is, in fact, the second law of thermodynamics.

Like the first law, the second law can be stated in several ways. One important consequence: the second law explains why spontaneous exothermic reactions are so common. In exothermic reactions, the heat released by the reaction increases the disorder of the surroundings, and the overall entropy change is positive, making the reaction spontaneous. …