A certain half-reaction has a standard reduction potential E0d=-1.07 V. An engin
ID: 1046010 • Letter: A
Question
A certain half-reaction has a standard reduction potential E0d=-1.07 V. An engineer proposes using this half-reaction at the anode of a galvanic cell that must provide at least 1.20 V 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. potential that the haif-reaction used at yes, there is a minimum. E. red ?? re cathode of this cell can have? If so, check the "yes" box and calculate wer to 2 ? no minimum O yes, there is a maximum. the cathode of this ceil can have? if so, check the "yes" box and calculate decimal places. 1 there is no upper imit Round your answer to2 O no maximum that could be 30 2 3Explanation / Answer
The given half cell will work as the anode of the galvanic cell. Oxidation occurs at the anode and the standard oxidation potential E0ox = -E0red. Therefore, the given half cell will have oxidation potential E0ox = -(-1.07 V) = +1.07 V.
The cell potential is given as E0cell = E0red + E0ox and the cell potential will have a value of atleast 1.20 V. Therefore, put E0cell = 1.20 V and get
E0red = E0cell – E0ox = (1.20 V) – (1.07 V) = 0.13 V.
If the cathode half cell has a reduction potential less than 0.13 V, then the cell potential of the galvanic cell will fall below 1.20 V. Hence, the cathode half cell must have a minimum standard reduction potential of +0.13 V (ans).
The cell is supposed to deliver atleast 1.20 V power. However, the cell can deliver more than 1.20 V power. Say, the cell delivers 1.30 V power. Then putting E0cell = 1.30 V, we have,
E0red = (1.30 V) – (1.07 V) = 0.23 V.
Hence, the cathode half cell will have no maximum reduction potential and the engineer can choose an appropriate cathode that will deliver atleast 0.13V or more power (ans).