What is the entropy for an irreversible adiabatic process?

In summary, the change in entropy is zero for a reversible adiabatic process, while it increases for irreversible processes. This is because irreversible processes involve dissipative forces, which increase the entropy. It is not possible to have an irreversible process that is also adiabatic, as adiabatic processes involve no heat transfer, while irreversible processes involve dissipative forces that generate heat. Examples of irreversible processes include friction, diffusion, and mixing.
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Homework Statement



The change in entropy is zero for:
A. reversible adiabatic processes
B. reversible isothermal processes
C. reversible processes during which no work is done
D. reversible isobaric processes
E. all adiabatic processes

Homework Equations



## dS = \frac{dQ}{T} ##

The Attempt at a Solution



The answer here is A.

But intuitively, I don't understand why it is that the entropy is zero only for a reversible adiabatic process.

What is it about irreversible processes that make the entropy increase? Is it that we can't have irreversiable processes that are adiabatic? Any examples to provide that can help me with intuition here?
 
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1. What is entropy in the context of thermodynamics?

Entropy is a measure of the disorder or randomness in a system. In thermodynamics, it represents the amount of energy that is unavailable for work in a system.

2. What is an irreversible adiabatic process?

An irreversible adiabatic process is a thermodynamic process in which there is no exchange of heat between the system and its surroundings, and it cannot be reversed to its initial state without the input of external energy.

3. How is entropy related to an irreversible adiabatic process?

In an irreversible adiabatic process, the entropy of the system increases due to the lack of heat exchange and the irreversibility of the process. This increase in entropy is a result of the system becoming more disordered.

4. Is the entropy for an irreversible adiabatic process always increasing?

Yes, the second law of thermodynamics states that the entropy of an isolated system always increases over time, and an irreversible adiabatic process is a perfect example of this principle.

5. Can the entropy of a system decrease during an irreversible adiabatic process?

No, the increase in entropy in an irreversible adiabatic process is a fundamental law of thermodynamics and cannot be reversed. The only way to decrease the entropy of a system is by inputting external energy, which would make the process reversible and not adiabatic.

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