Question

A certain half-reaction has a standard reduction potential E⁰ʀᴇᴅ = 0.83 V. An engineer proposes using this half-reaction at the anode of a galvanic cell that must provide at least 0.80V of electrical power. The cell will operate under standard conditions. Note for advanced students: assume the engineer requires this half-reaction to happen at the anode of the cell.

(1) Is there a minimum standard reduction potential that the half-reaction used at the cathode of this cell can have? If so, write "yes" and calculate the minimum. Round your answer to 2 decimal places. If there is no lower limit, write "no".
(2) Is there a maximum standard reduction potential that the half-reaction used at the cathode of this cell can have? If so, write "yes" and calculate the minimum. Round your answer to 2 decimal places. If there is no lower limit, write "no".

Answer 1

For 1: The minimum standard electrode potential at cathode is -0.03 V

For 2: The maximum standard electrode potential at cathode is 1.63 V

Step-by-step explanation:

To calculate the
`E^o_(cell)` of the reaction, we use the equation:

`E^o_(cell)=E^o_(cathode)-E^o_(anode)`

We are given:

`E^o_(cell)` = Standard electrode potential of the cell = 0.80 V

• For 1:

To make the standard reduction potential at the cathode minimum, we take the standard reduction potential at anode as (0.83 V)

Putting values in above equation, we get:

`0.80=E^o_(cathode)-(0.83)\\\\E^o_(cathode)=0.80-0.83=-0.03V`

Hence, the minimum standard electrode potential at cathode is -0.03 V

• For 2:

To make the standard reduction potential at the cathode maximum, we take the standard reduction potential at anode as (-0.83 V)

Putting values in above equation, we get:

`0.80=E^o_(cathode)-(-0.83)\\\\E^o_(cathode)=0.80+0.83=1.63V`

Hence, the maximum standard electrode potential at cathode is 1.63 V