Given below are two statements:
Statement I: Ecell should have a positive value for the cell to function
Statement II: \(E_{cathode} < E_{anode}\)
In the light of the above statements, choose the most appropriate answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is option 3. Statement I is correct and Statement II is incorrect.
Statement I is correct. For an electrochemical cell to function as a galvanic cell and generate electricity, the cell potential (\(E_{cell}\)) must be positive. A positive \(E_{cell}\) indicates that the cell reaction is spontaneous, and it can drive the flow of electrons through the external circuit. The cathode undergoes reduction and has a more positive potential compared to the anode.
Statement II is false. In a galvanic cell, the cathode's electrode potential (\(E_{cathode}\)) is actually more positive (greater) than the anode's electrode potential (\(E_{anode}\)). This is because the cell potential (\(E_{cell}\)) is calculated as the difference between the cathode potential and the anode potential:
\[E_{cell} = E_{cathode} - E_{anode}\]
Since \(E_{cathode}\) is greater than \(E_{anode}\) in a galvanic cell, \(E_{cell}\) is positive, and the cell can function spontaneously.
In summary, Statement I is correct, as a positive \(E_{cell}\) is necessary for a functioning galvanic cell. However, Statement II is false, as the cathode's potential is more positive than the anode's potential in a galvanic cell. The correct answer is 3.