Question

Calculate ?cell for the following concentration cell ? Cu(s) | Cu2+ (aq, 0.025M) ? Cu2+ (aq, 0.30M) | Cu(s)

Cu2+ (aq) + 2e- ? Cu(s) ? ?° = 0.340V

A)0.0638 V

B)-0.0734 V

C)0.0734 V

D)-0.0319 V

E)0.0139 V

Answer 1

cell contain same electrodes with
different electrolyte concentration .Such ells are known
as concentration cell.Current flow will happen by
flow of electrons from lower concentration half cell to
high concentration half cell.

we have
Ecell = E0cell-0.0591/n log Q

This type of cell E0cell= 0 [since both are same electrods]
So Ecell = -RT/nFlog Q** is the formula

Q is the reaction quotient = [product]/[reactant]

Cell voltage for concentration cell
Ecell = - 0.0592/n *log[Cu2+(dil)/Cu2+(conc)]
=- 0.0592/2*log[0.025/0.3] = -0.0319 V
**
option D)-0.0319 V