Which statement correctly describes a characteristic of spontaneous processes in terms of entropy?

• A. They lead to a decrease in entropy
• B. They lead to an increase in entropy
• C. They have no effect on entropy
• D. They are independent of entropy changes

Answer: (B)

Spontaneous processes are characterized by a tendency toward an increase in entropy, which is a measure of the disorder or randomness in a system. According to the second law of thermodynamics, in an isolated system, the total entropy can never decrease over time; it can only increase or remain the same. This means that spontaneous processes, which occur naturally without external influence, are typically accompanied by an increase in the overall entropy of the universe.

For example, when ice melts into water, the ordered arrangement of water molecules in the solid state becomes less ordered in the liquid state, leading to an increase in entropy. Similarly, when gases expand into a vacuum, the molecules disperse, resulting in a greater degree of disorder, which is a hallmark of increased entropy.

This natural inclination toward greater disorder is what makes option B the correct choice, as it encapsulates the fundamental understanding of spontaneous processes in thermodynamic terms.