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 spontaneous galvanic cell has a positive cell potential (\( E_{\text{cell}} \)). If an external potential (\( E_{\text{ext}} \)) exceeding the cell potential is applied, the cell's reaction reverses, making it function as an electrolytic cell. This transition signifies the cell consuming electrical energy to facilitate a non-spontaneous reaction, a defining characteristic of electrolytic cells. Consequently, the condition for a galvanic cell to operate as an electrolytic cell is: \( E_{\text{ext}}>E_{\text{cell}} \).
Final Answer: \[\boxed{\text{The correct answer is (3), } E_{\text{ext}}>E_{\text{cell}}. \text{}}\]