Entropy change in a reversible adiabatic process

In summary, the entropy change in a reversible adiabatic process is the change in disorder or randomness of a system with no heat transfer. It is directly related to the change in temperature through a specific equation and is significant in thermodynamics as it represents an ideal process for determining maximum work. Compared to an irreversible adiabatic process, the entropy change is always zero in a reversible process. It cannot be negative due to the slow and equilibrium nature of the process.
  • #1
Bipolarity
776
2
For a reversible process, I imagine it is correct to say that

[itex] dS = \frac{dq}{T} [/itex] where all quantities refer to system quantities (not the surrounding).

However, for an adiabatic process, [itex] dq = 0 [/itex].

Thus, should it be the case that for an adiabatic reversible process,

[itex] dS = \frac{dq}{T} = \frac{0}{T} = 0 [/itex]

Please correct me if I am wrong, and point out the flaws in my reasoning.

BiP
 
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  • #2
Entirely correct.
 

1. What is the definition of entropy change in a reversible adiabatic process?

The entropy change in a reversible adiabatic process is the change in the disorder or randomness of a system when it undergoes a reversible adiabatic process, meaning there is no exchange of heat with the surroundings.

2. How is the entropy change related to the change in temperature in a reversible adiabatic process?

In a reversible adiabatic process, the entropy change is directly related to the change in temperature through the equation ΔS = nCv ln(T2/T1), where n is the number of moles of the gas and Cv is the heat capacity at constant volume.

3. What is the significance of a reversible adiabatic process in thermodynamics?

A reversible adiabatic process is significant in thermodynamics because it represents a theoretical ideal process that is used to determine the maximum work that can be obtained from a system. It also allows for the calculation of the change in entropy without any heat transfer, making it a useful tool for studying the behavior of gases.

4. How does the entropy change in a reversible adiabatic process compare to that in an irreversible adiabatic process?

In a reversible adiabatic process, the entropy change is zero, as there is no heat transfer and the process is carried out slowly enough that the system remains in thermal equilibrium. In an irreversible adiabatic process, the entropy change is always positive, as there is some degree of irreversibility and the system does not remain in equilibrium.

5. Can the entropy change in a reversible adiabatic process be negative?

No, the entropy change in a reversible adiabatic process cannot be negative. This is because the process is carried out slowly enough that the system remains in equilibrium and there is no heat transfer, resulting in a change in entropy of zero or a positive value.

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