Question

Question No. 28
A concentration cell is constructed by
placing identical Cu electrodes in two Cu2+
solutions. If the concentrations of the two
Cu2+ solutions are 1.0 M and 0.0020 M,
what will be the potential of the cell?
Answer
A.
0.080 V
0.159 V
B.
C.
0.020 V
0.030 V
D.​

Answer 1

Recall that the actual free-energy change for a reaction under nonstandard conditions, ΔG , is given as follows:

ΔG=ΔG°+RTlnQ(11.4.1)

We also know that ΔG=−nFEcell (under non-standard confitions) and ΔGo=−nFEocell (under standard conditions). Substituting these expressions into Equation 11.4.1 , we obtain

−nFEcell=−nFEocell+RTlnQ(11.4.2)

Dividing both sides of this equation by −nF ,

Ecell=E∘cell−(RTnF)lnQ(11.4.3)