Ideal gases A (red spheres) and B (blue spheres) occupy two separate bulbs. The contents of both bulbs constitute the initial state of an isolated system. Consider the process that occurs when the stopcock is opened.

(c) How dpes this process illustrate the second law of thermodynamics?

Key Concepts

Second Law of Thermodynamics

The Second Law of Thermodynamics states that in any energy transfer or transformation, the total entropy of an isolated system can never decrease over time. This means that natural processes tend to move towards a state of greater disorder or randomness. In the context of the question, when the stopcock is opened, the gases A and B will mix, leading to an increase in entropy as the system transitions from a more ordered state (separate gases) to a more disordered state (mixed gases).

Entropy

Entropy is a measure of the amount of disorder or randomness in a system. It quantifies the number of ways a system can be arranged while still maintaining the same energy level. In the scenario presented, the initial state has lower entropy due to the separation of gases, while the final state after opening the stopcock has higher entropy as the gases mix, illustrating the natural tendency towards increased disorder.

Isolated System

An isolated system is one that does not exchange matter or energy with its surroundings. In the context of the question, the two bulbs containing gases A and B represent an isolated system where the only interaction occurs when the stopcock is opened. This concept is crucial for understanding how the gases behave and how the entropy changes, as the system's isolation ensures that the total energy remains constant while the entropy increases.