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Question #44751
The Question
A aqueous solution of (initial concentration ) is subjected to electrolysis at using inert electrodes and a constant current of . Simultaneously, in the presence of a homogeneous catalyst, undergoes a pseudo-first-order disproportionation into and with a rate constant . The anodic electrolysis reaction strictly oxidizes to and . Assuming no volume change and current efficiency, what is the total moles of evolved from the solution by the time is completely depleted? (Given: )
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Mechanism_Trap
Don't get tricked by the process! Learn the mechanical traps used in competitive exam questions.
Concepts Behind This Question
Faraday's First and Second Laws|Pseudo-First Order Kinetics
Why This Question Is Tricky
Common Mistakes
This problem tests the coupling of Faraday's Laws of Electrolysis with First-Order Chemical Kinetics.
The 'Hidden Variable' is the time-dependent concentration of the reactant, which simultaneously undergoes a zero-order depletion (constant current electrolysis) and a first-order depletion (chemical decomposition).
Students often fall into the trap of treating the two processes independently or assuming the chemical decomposition rate is constant (zero-order), which leads to an incorrect total time and mass distribution (Option B).
Furthermore, failing to account for the different stoichiometric ratios of O2 production in the two parallel pathways leads to additional errors.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Electrochemistry - Class 12 |
| Concept | Faraday's First and Second Laws |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |