[skibum143]

An electrochemical cell consists of two chambers
connected by the usual assortment of wires, salt bridge,
etc. (See diagram.) Both chambers contain copper
electrodes in a solution of copper sulfate. In Chamber A,
the initial concentration of Cu2+ is 0.7 M, while in
Chamber B it is 0.10 M. Both chambers have the same
volume, and temperature = 25 C (298 K).

What is E cell?

E0 = Zero
E cell = E0 - RT/nF ln Q
Q = 0.1/0.7
E cell = 0 - 8.314*298 / 2*96485 ln (0.1/0.7)  =  2.5E-2 V

But the answer should be 7.2E-3 V?? Not sure where I'm wrong...

[Borek]

2.5e-2 or 2.5e-3?

But I agree 72 mV looks off. That would require much higher concentration difference.