Question

The reaction is spontaneous if the cell potential is

• A. positive
• B. negative
• C. zero
• D. infinite

Hint:

A positive cell potential indicates that the redox reaction will occur spontaneously in the forward direction.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The relationship between Gibbs free energy and cell potential is \(\Delta G = -nFE_{cell}\).
Step 2: Detailed Explanation:
For a spontaneous reaction, \(\Delta G<0\). Since \(-nF\) is negative, \(E_{cell}\) must be positive to make \(\Delta G\) negative.
\(E_{cell}>0\) ⇒ \(\Delta G<0\) ⇒ spontaneous reaction.
\(E_{cell}<0\) ⇒ \(\Delta G>0\) ⇒ non-spontaneous.
\(E_{cell} = 0\) ⇒ \(\Delta G = 0\) ⇒ equilibrium.
Step 3: Final Answer:
A reaction is spontaneous when the cell potential is positive, option (A).