At the vicinity of equilibrium (thermo)

[Proust]

Hello everyone,

Below is one paragraphe from my thermo textbook:

Equilibrium for Aⁱ but not for T (Xⁱ_A = Xⁱ_B but, for example : T_A > T_B). Thus, for U and S, we have a gap in relation to the equilibrium : U_A = U_Aeq + [itex]\delta[/itex]U_A,U_B = U_Beq + [itex]\delta[/itex]U_B

Ai is state variables such as V,l, ect. T is temperature.

I don't quite understand why there is not a second situation where Ai is the same but T is different? Why it's not mentioned here?

Thanks a lot.

 

[anathema]

Hello there,

Thank you for sharing a paragraph from your thermo textbook. From what I understand, the paragraph is discussing the concept of equilibrium in relation to state variables (Ai) and temperature (T). The author is stating that for state variables such as volume and length, the equilibrium is achieved when the values of these variables are the same for both systems (XiA = XiB). However, for temperature, the equilibrium is not achieved when the values are the same (TA = TB), but rather when one temperature is greater than the other (TA > TB).

To answer your question, there may be situations where the state variables are the same but the temperature is different. However, the focus of this paragraph is on the concept of equilibrium in relation to state variables and temperature, and the author is simply using an example to illustrate the point. It is possible that in other situations, the temperature may also be the same for both systems, but that is not the main focus of this paragraph.

I hope this helps clarify the concept for you. Let me know if you have any further questions.