Derive an equation for the equilibrium constant $K_C$ of any galvanic cell (redox reaction) and also state its uses.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) According to the Nernst equation,for any redox reaction at equilibrium,the cell potential $E_{\text{cell}}$ becomes $0.0 \ V$ and the reaction quotient $Q$ becomes equal to the equilibrium constant $K_C$.
The Nernst equation is given by:
$E_{\text{cell}} = E_{\text{cell}}^{o} - \frac{0.059}{n} \log Q$
At equilibrium,$E_{\text{cell}} = 0$ and $Q = K_C$,so:
$0 = E_{\text{cell}}^{o} - \frac{0.059}{n} \log K_C$
Rearranging for $E_{\text{cell}}^{o}$:
$E_{\text{cell}}^{o} = \frac{0.059}{n} \log K_C$
Solving for $\log K_C$:
$\log K_C = \frac{n \times E_{\text{cell}}^{o}}{0.059}$
Thus,$K_C = \text{antilog} \left( \frac{n \times E_{\text{cell}}^{o}}{0.059} \right)$
Where $n$ is the number of electrons exchanged and $E_{\text{cell}}^{o} = E_{\text{cathode}}^{o} - E_{\text{anode}}^{o}$.
Uses:
$(i)$ The equilibrium constant $K_C$ can be calculated by measuring the standard cell potential.
$(ii)$ The magnitude of $K_C$ indicates the extent of the reaction; a high value of $K_C$ implies that the forward reaction is favored,resulting in a higher yield of products.

Explore More

Similar Questions

Calculate $pH$ of $HCl$ solution at $298\,K$ temperature for the following cell: $Pt_{(s)} \mid H_2 \,(1\,bar) \mid HCl\,(xM) \parallel Cu^{2+}\,(0.02\,M) \mid Cu_{(s)}$. Given that the standard cell potential $E^{\circ}_{cell} = 0.34\,V$ and the measured cell potential $E_{cell} = 0.45\,V$.

Difficult
View Solution

The $emf$ of a $Daniel$ cell at $298 \ K$ is ${E_1}$ for the cell reaction $Zn|ZnSO_4(0.01 \ M)||CuSO_4(1.0 \ M)|Cu$. When the concentration of $ZnSO_4$ is $1.0 \ M$ and that of $CuSO_4$ is $0.01 \ M$,the $emf$ changes to ${E_2}$. What is the relationship between ${E_1}$ and ${E_2}$?

Consider the electrochemical cell shown in the figure where a metal electrode $(M)$ undergoes a redox reaction by forming $M^{+}$ $(M \rightarrow M^{+} + e^{-})$. The cation $M^{+}$ is present in two different concentrations $c_{1}$ and $c_{2}$. Which of the following statements is correct for generating a positive cell potential?

By how much will the potential of the half-cell $Cu^{2+}/Cu$ change if the solution is diluted to $100$ times at $298 \ K$?

Calculate the potential of a hydrogen electrode in contact with a solution whose $pH = 10$.

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo