Irreversible process

Definition

An irreversible process is a thermodynamic process that cannot return both the system and the surroundings to their original states. Irreversibility often results from factors like friction, unrestrained expansion, or heat transfer through a finite temperature difference.

5 Must Know Facts For Your Next Test

1. In an irreversible process, entropy always increases.
2. Irreversible processes are more common in real-life scenarios compared to reversible processes.
3. Heat engines operating between two reservoirs can never be 100% efficient due to irreversibilities.
4. Examples of irreversible processes include natural phenomena such as mixing of gases, spontaneous chemical reactions, and natural heat flow from hot to cold bodies.
5. The Second Law of Thermodynamics asserts that all natural processes are irreversible.

Review Questions

• Why does entropy increase in an irreversible process?
• How does the efficiency of a heat engine relate to the concept of irreversibility?
• Give one example of an irreversible process and explain why it is considered irreversible.

Related terms

Entropy:

A measure of the disorder or randomness in a system, often increasing in irreversible processes.

Second Law of Thermodynamics:

A law stating that entropy in an isolated system always increases over time and energy transformations are not completely efficient.

Heat Engine: \text{A device that converts thermal energy into mechanical work, often limited by inefficiencies due to irreversibilities.}