Question

The unit of \( E_{\text{cell}} \) is

• A. V m$^{-1}$
• B. S cm$^{-1}$
• C. V
• D. S cm$^{-2}$ mol$^{-1}$

Hint:

The cell potential (\( E_{\text{cell}} \)) is always expressed in volts (V) in electrochemical calculations.

Answer 1

The Correct Option is C

To identify the correct unit for \( E_{\text{cell}} \), we must understand what \( E_{\text{cell}} \) represents. In electrochemistry, \( E_{\text{cell}} \) is known as the cell potential or electromotive force (emf) of an electrochemical cell. It represents the potential difference that drives electrons from the anode to the cathode in a cell.

The standard unit of electric potential or electromotive force is the volt (V).

Let's analyze the options provided and justify why the correct answer is V:

• V m^-1: This is the unit for electric field strength, not potential difference. Thus, it is not suitable for \( E_{\text{cell}} \).
• S cm^-1: This unit stands for conductivity, which is unrelated to the cell potential.
• V: This is the standard SI unit for potential difference or electromotive force, making it the correct unit for \( E_{\text{cell}} \).
• S cm^-2 mol^-1: This is not a standard unit for any fundamental electrochemical or electrical property of a cell. It could represent a complex quantity, but it does not apply to cell potential.

Thus, the unit of \( E_{\text{cell}} \) is V.