please see the attachment.
So people, I am writing so the other who did not attend class can also have the opportunity for the extra point.
What I want? I want you to show that when two systems, 1 and 2, are brought into contact and you allow energy to flow from 1 to 2 and particles to flow from 2 to 1, the equilibrium conditions will be:
(A) t1 = t2
(B) 1/t2 (Ds1/DN1) = 1/t1(Ds2/Dn2)
PS.: I do not remember if when I re-wrote the condition (B) in class today I swapped temperatures 1 and 2. Anyways, the conditions above are the ones you have to find.
PS2.: Why it is interesting to write 1/