Question

A galvanic cell behaves as an electrolytic cell when?

• A. \( E_{\text{cell}} = E_{\text{ext}} \)
• B. \( E_{\text{cell}} = 0 \)
• C. \( E_{\text{ext}}>E_{\text{cell}} \)
• D. \( E_{\text{cell}}>E_{\text{ext}} \)

Hint:

When an external voltage greater than the cell potential is applied, the galvanic cell functions as an electrolytic cell.

Answer 1

The Correct Option is C

A galvanic cell is spontaneous, and its cell potential (\( E_{\text{cell}} \)) is positive. However, when an external potential (\( E_{\text{ext}} \)) greater than the cell potential is applied, the cell will reverse its spontaneous reaction, and it will start behaving like an electrolytic cell. In this case, the cell consumes electrical energy to drive a non-spontaneous reaction, which is characteristic of an electrolytic cell.
Thus, the correct condition for a galvanic cell to behave as an electrolytic cell is: \( E_{\text{ext}}>E_{\text{cell}} \).
Final Answer: \[ \boxed{\text{The correct answer is (3), } E_{\text{ext}}>E_{\text{cell}}.} \]