temperature of a reversible reaction

[Samantha Chung 4I]

It was mentioned today in lecture that the temperature of an reversible reaction both inside and outside the system has to be constant, why is this the case?

[Jim Brown 14B Lec1]

The reaction is not isolated and takes place in a heat reservoir. This way, even if the reaction is exothermic, the overall temperature will remain the same at the beginning and the end of the reaction.

[Jake Gordon 1A]

The delta T is essentially 0 because of the heat resevoir. When we talk about isothermal reversible expansion, isothermal refers to a constant "same" temperature even though as stated above their is a slight change in temp that is quickly replaced by the surroundings.

[Elizabeth Gallmeister 1A]

And from there, if deltaT is zero, it follows that deltaU = 0 and therefore q = -w.