Identify the correct equations for the emf of a cell at equilibrium.
- \(E^0_{cell} = \frac{2.303RT}{nF}logK_c\)
- \(E^0_{cell} =\frac{\Delta G}{nF}\)
- \(E_{cell} = E^0_{cell} - \frac{RT}{nF}ln\frac{[Products]}{[Reactants]}\)
- \(E^0_{cell} = E^0_{left} – E^0_{right}\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is option 1. (A) and (C) only.
We know the Nernst equation is
\(E_{cell} = E^0_{cell} - \frac{RT}{nF}ln Q\)
\(E_{cell} = E^0_{cell} - \frac{RT}{nF}ln\frac{[Products]}{[Reactants]}\) [Since, \(Q = \frac{[Product]}{[Reactant]}\)]
At equilibrium, \(E_{cell}= 0\) and \(Q = K_c\)
\(E^0_{cell} = \frac{2.303RT}{nF}logK_c\)
\(\Delta G^0 = -nFE^0_{cell}\)
\(E^0_{cell} = E^0_{right} - E^0_{left}\)