<u>Answer:</u>
<u>For 1:</u> The largest positive cell potential is of cell having 1st and 4th half reactions.
<u>For 2:</u> The standard electrode potential of the cell is 1.539 V
<u>For 3:</u> The smallest positive cell potential is of cell having 3rd and 4th half reactions. The standard electrode potential of the cell is 0.46 V
<u>Explanation:</u>
The substance having highest positive potential will always get reduced and will undergo reduction reaction.
We are given:
Substance getting oxidized always act as anode and the one getting reduced always act as cathode.
To calculate the of the reaction, we use the equation:
- <u>Cell having 1st and 2nd half reactions:</u>
Silver has higher electrode potential. So, this will undergo reduction reaction and act as anode. Copper will undergo oxidation reaction and act as cathode.
- <u>Cell having 1st and 3rd half reactions:</u>
Silver has higher electrode potential. So, this will undergo reduction reaction and act as anode. Nickel will undergo oxidation reaction and act as cathode.
- <u>Cell having 1st and 4th half reactions:</u>
Silver has higher electrode potential. So, this will undergo reduction reaction and act as anode. Chromium will undergo oxidation reaction and act as cathode.
- <u>Cell having 2nd and 3rd half reactions:</u>
Copper has higher electrode potential. So, this will undergo reduction reaction and act as anode. Nickel will undergo oxidation reaction and act as cathode.
- <u>Cell having 3rd and 4th half reactions:</u>
Nickel has higher electrode potential. So, this will undergo reduction reaction and act as anode. Chromium will undergo oxidation reaction and act as cathode.
Hence,
<u>For 1:</u> The largest positive cell potential is of cell having 1st and 4th half reactions.
<u>For 2:</u> The standard electrode potential of the cell is 1.539 V
<u>For 3:</u> The smallest positive cell potential is of cell having 3rd and 4th half reactions. The standard electrode potential of the cell is 0.46 V