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

Considering the cell $Cu | Cu^{2+} || Ag^{+} | Ag$,what happens to the $emf$ if the concentrations of both $Cu^{2+}$ and $Ag^{+}$ ions are increased by a factor of $10$?

Give the Nernst equation for the electrode potential $E_{(M^{n+} \mid M)}$.

On diluting the concentration of $Cl^{-}$ ions by ten times in a calomel electrode,its reduction potential at $298 \ K$ is -

Which of the following is correct as a Nernst equation for the given electrochemical cell ?
$Mg_{(s)}|Mg_{(aq)}^{2+}(0.1 \ M)||Cl_{(aq)}^{-}(0.1 \ M)|Cl_{2_{(g)}}(1 \ bar)|Pt_{(s)}$

In a cell that utilises the reaction $Zn_{(s)} + 2H^{+}_{(aq)} \to Zn^{2+}_{(aq)} + H_{2_{(g)}}$,addition of $H_2SO_4$ to the cathode compartment will:

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