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

Answer:

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

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