Isothermal Definition

[Maria George 3K]

In an irreversible expansion, the temperature changes and then returns back to what it was at the beginning (e.g. temperature goes down, then back up). Would this be considered an isothermal "change," since Tf-Ti is 0?
Or does the pathway matter, and since temperature was not constant the whole way through, it's not an isothermal "change"?

(meaning does the meaning of "change" here just refer to final and initial states, or the whole process)?

[ivy knabe 3i]

since reversible or irreversible expansion is essentially work done, work is not a state function, it is a path function, so the isothermal change is the whole process of expansion

[Andres Medrano 1I]

Hey! I do not think it would be considered isothermal. Isothermal means there is constant temperature throughout the problem. Yes, the scenario you explained had temperature at the same start and finish point, but it does not necessarily mean that the temperature remained the same throughout the rxn.

[Ashely_Pavon_2E]

An irreversible expansion would be considered an isothermal process, since the overall reaction remains the same.

[Destiny Caldwell 3J]

In the context of irreversible expansion, the term "isothermal change" typically refers to a process where the temperature remains constant throughout the entire expansion. Even though the final and initial temperatures may be the same, if the temperature fluctuates during the process, it wouldn't be considered an isothermal change. Therefore, the pathway matters, and in this case, since the temperature changes during the expansion, it wouldn't be considered isothermal.