A Cell is prepared by dipping a copper rod in 0.01 M copper sulphate solution, and zinc rod in 0.02 M ZnSO₄ solution. The standard reduction potentials of copper and zinc are + 0.34 V and – 0.76 V respectively.
(a) What will be the cell reaction?
(b) How will the cell be represented?
(c) What will be the emf. of the cell?

Solution

(a) As E°_Zn²⁺/Zn < E°_Cu²⁺/Cu . Zinc electrode acts as anode and copper electrode acts as a cathode. The cell reaction is
Zn(s) + Cu²+(aq) (0.01 M) → Zn²⁺(aq) (0.02 M) + Cu(s)
(b) The cell is represented as
Zn(s) | Zn²+(aq) (0.02 M) || Cu²+(aq) (0.01 M) + Cu(s)
(c) The emf of the cell can be calculated by using Nernst equation
$E = E ° - \frac{0.059}{n} \log \frac{[{Zn}^{2 +}]}{[{Cu}^{2 +}]} E = + 1.10 - \frac{0.059}{2} \log (\frac{0.02}{0.01}) E = + 1.10 - \frac{0.059}{2} \times 0.301 E = + 1.10 - 0.0089 or E = + 1.091 V$

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For Daily Free Study Material Join wiredfaculty

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Some More Questions From Electrochemistry Chapter

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?

Suggest a list of metals that are extracted electrolytically.

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Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.

Suggest two materials other than hydrogen that can be used as fuels in fuel cells.

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

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.

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