SATHEE: Electrochemistry 1 Question 33

Electrochemistry 1 Question 33

32. The following electrochemical cell has been set-up :

$\begin{aligned} Pt (1) | {Fe}^{3 +}, {Fe}^{2 +} (a = 1) | {Ce}^{4 +}, {Ce}^{3 +} (a = 1) ∣ Pt (2) \\ E^{\circ} ({Fe}^{3 +}, {Fe}^{2 +}) = 0.77 V \\ and E^{\circ} ({Ce}^{4 +}, {Ce}^{3 +}) = 1.61 V \end{aligned}$

If an ammeter is connected between the two platinum electrodes, predict the direction of flow of current, will the current increases or decreases with time?

(2000, 2M)

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Solution:

Since, activities of all the ions are unity, $E_{cell} = E_{cell}^{\circ}$ . Also, left hand electrode is at lower reduction potential, it act as anode and

$E^{\circ} = E^{\circ} ({Ce}^{4 +}, {Ce}^{3 +}) - E^{\circ} ({Fe}^{3 +}, {Fe}^{2 +}) = 0.84$

i.e. electrons will flow from left to right hand electrode and current from right hand electrode $[Pt (2)]$ to left hand electrode $[Pt (1)]$ .

Also, $E = E^{\circ} - 0.0592 \log \frac{[{Fe}^{3 +}] [{Ce}^{3 +}]}{[{Fe}^{2 +}] [{Ce}^{4 +}]}$

As electrolysis proceeds, $E$ will decrease and therefore, current.

Electrochemistry 1 Question 33

32. The following electrochemical cell has been set-up :

Solution:

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Electrochemistry 1 Question 33

32. The following electrochemical cell has been set-up :

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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