During the electrolysis of 0.1 M `CuSO_(4)` solution using coppepr electrodes, a depletion of `[Cu^(2+)]` occurs near the cathode with a corresponding excess near the anode, owing to inefficient stirring of the solution. If the local concentration of `[Cu^(2+)]` near the anode and cathode are respectively 0.12 M and 0.08 M, calcualte the back emf developed. Temperature = 298 K.

Options

A. 22 mV
B. 5.2 mV
C. 29 mV
D. 59 mV

Answer

B

Explanation

`E_(cell)=E_(cell)^(0)-(0.0591)/(2)log_(10)(([Cu^(2+)]_("cathode"))/([Cu^(2+)]_("anode")))`
`E_(cell)^(0)=0`
`E_(cell)=-(0.591)/(2)log_(10)((0.08)/(0.12))=+5.2V`.