Write the Nernst equation and emf of the following cells at 298 k.
Mg(s) | Mg²⁺ (0.001 M) || Cu²⁺ (0.0001 M) | Cu(s)

Solution

For an electrochemical cell reaction
aA + bB → cC + dD
The Nernst’s equation for cell reaction is
$E_{cell} = {E^{0}}_{cell} - \frac{0.059}{n} \log \frac{{[C]}^{c} {[D]}^{d}}{{[A]}^{a} {[B]}^{b}}$
The values of a, b, c, d and n can be obtained from the balanced cell reaction. (i) Anode reaction:
$Mg (s) \to {Mg}^{2 +} (aq) + 2 e^{-}$
Cathode reaction:
${Cu}^{2 +} (aq) + 2 e^{-} \to Cu (s)$
Overall cell reaction:
$Mg (s) + {Cu}^{2 +} (aq) \to {Mg}^{2 +} (aq) + Cu (s)$
Here, n= 2, ${E^{0}}_{cell} = {E^{0}}_{cathode} - {E^{0}}_{anode} = 0.34 V - (- 2.37) V = 2.71 V$
The Nernst equation for E_cell at 298 can be written as
$E_{cell} = {E^{0}}_{cell} = - \frac{0.059}{n} \log \frac{10^{- 3}}{10^{- 4}} = 2.71 - 0.0295 = 2.68 V$

Some More Questions From Electrochemistry Chapter

The molar conductivity of 0.025 mol L^–1methanoic acid is 46.1 S cm² mol^–1. Calculate its degree of dissociation and dissociation constant. Give λ°(H⁺) = 349.6 S cm²mol^–1 and λ° (HCOO^– ) = 54.6 s cm² mol^–1.

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Electrochemistry

Write the Nernst equation and emf of the following cells at 298 k.
Mg(s) | Mg²⁺ (0.001 M) || Cu²⁺ (0.0001 M) | Cu(s)

Some More Questions From Electrochemistry Chapter

How would you determine the standard electrode potential of the system Mg²⁺/Mg?

Can you store copper sulphate solutions in a Zinc pot?

Why does the conductivity of a solution decrease with dilution?

Suggest a way to determine the Λ°_m value of water.

The molar conductivity of 0.025 mol L^–1methanoic acid is 46.1 S cm² mol^–1. Calculate its degree of dissociation and dissociation constant. Give λ°(H⁺) = 349.6 S cm²mol^–1 and λ° (HCOO^– ) = 54.6 s cm² mol^–1.

If the current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons flow through the wire?

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For Daily Free Study Material Join wiredfaculty

Electrochemistry

Write the Nernst equation and emf of the following cells at 298 k.Mg(s) | Mg2+ (0.001 M) || Cu2+ (0.0001 M) | Cu(s)

Some More Questions From Electrochemistry Chapter

How would you determine the standard electrode potential of the system Mg2+/Mg?

Can you store copper sulphate solutions in a Zinc pot?

Why does the conductivity of a solution decrease with dilution?

Suggest a way to determine the Λ°m value of water.

The molar conductivity of 0.025 mol L–1 methanoic acid is 46.1 S cm2 mol–1. Calculate its degree of dissociation and dissociation constant. Give λ°(H+) = 349.6 S cm2 mol–1 and λ° (HCOO– ) = 54.6 s cm2 mol–1.

If the current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons flow through the wire?

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Write the Nernst equation and emf of the following cells at 298 k.
Mg(s) | Mg²⁺ (0.001 M) || Cu²⁺ (0.0001 M) | Cu(s)

How would you determine the standard electrode potential of the system Mg²⁺/Mg?

Suggest a way to determine the Λ°_m value of water.

The molar conductivity of 0.025 mol L^–1methanoic acid is 46.1 S cm² mol^–1. Calculate its degree of dissociation and dissociation constant. Give λ°(H⁺) = 349.6 S cm²mol^–1 and λ° (HCOO^– ) = 54.6 s cm² mol^–1.