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Question #44750

Difficulty: 8/10 | 🟢 Free

The Question

Two electrolytic cells, X and Y, are connected in series. Cell X contains 500 mL500\text{ mL} of 0.30 M \ceCe(SO4)20.30\text{ M } \ce{Ce(SO4)2} in dilute \ceH2SO4\ce{H2SO4}, and Cell Y contains an aqueous solution of \ceCuSO4\ce{CuSO4}. A constant current is passed through the cells until 1.5875 g1.5875\text{ g} of \ceCu\ce{Cu} is deposited at the cathode of Cell Y. The electrolysis is then stopped. The resulting solution from Cell X is completely titrated with 0.10 M \ceFeSO40.10\text{ M } \ce{FeSO4} solution. What is the volume of \ceFeSO4\ce{FeSO4} solution required to reach the equivalence point?\n\n(Given: Atomic mass of \ceCu=63.5 g/mol\ce{Cu} = 63.5\text{ g/mol}, E\ceCe4+/Ce3+∘=+1.61 VE^\circ_{\ce{Ce^{4+}/Ce^{3+}}} = +1.61\text{ V}, E\ceCe3+/Ce∘=−2.34 VE^\circ_{\ce{Ce^{3+}/Ce}} = -2.34\text{ V}, E\ceH+/H2∘=0.00 VE^\circ_{\ce{H+/H2}} = 0.00\text{ V})

Options

  • A.

    1000 mL

  • B.

    1375 mL

  • C.

    1250 mL

  • D.

    500 mL

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Numerical_Precision

Improve calculation stamina and avoid rounding errors in high-stakes competitive examinations.

Concepts Behind This Question

Faraday's First and Second Laws|Variable Oxidation State Stability

Why This Question Is Tricky

Common Mistakes

The core trap tests the student's understanding of preferential discharge and variable oxidation states in electrochemistry.

Students often mechanically apply Faraday's First Law assuming metal deposition (\ceCe4++4e−−>Ce\ce{Ce^{4+} + 4e^- -> Ce}), leading to an incorrect n-factor of 4.

However, in aqueous acidic media, the reduction of \ceCe4+\ce{Ce^{4+}} stops at \ceCe3+\ce{Ce^{3+}} due to its extreme stability and highly negative standard reduction potential to the metallic state.

Recognizing that the n-factor is 1 for the electrolytic reduction of \ceCe4+\ce{Ce^{4+}} to \ceCe3+\ce{Ce^{3+}} is the 'Hidden Variable' required to correctly determine the remaining concentration for the subsequent redox titration.

Quick Facts About This Question

Question Information

SubjectChemistry
ChapterElectrochemistry - Class 12
ConceptFaraday's First and Second Laws
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree