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Question #44126
The Question
An electrochemical cell contains of an aqueous solution comprising and at . Electrolysis is performed using inert platinum electrodes by passing a constant current of for . The primary gas evolved at the anode is collected and completely reacted with an excess of hot, concentrated .
Assuming current efficiency for the kinetically favored anodic process, identify the major chlorine-containing oxyanion formed in the final solution and calculate its amount.
(Given: ; Standard oxidation potentials: , , )
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
Oxidation State Extremes|Electrolysis Product Prediction
Why This Question Is Tricky
Common Mistakes
This question tests the critical distinction between thermodynamic and kinetic control in electrochemistry, specifically the 'Overpotential Effect'.
Students often rely solely on Standard Oxidation Potentials, incorrectly predicting that water will oxidize to oxygen gas because its oxidation potential is less negative than that of chloride.
However, the kinetic barrier (overpotential) for oxygen evolution on platinum electrodes is exceptionally high, making chlorine evolution the favored pathway in concentrated brine.
Additionally, it traps students who confuse the disproportionation products of halogens in alkali; cold/dilute sodium hydroxide yields hypochlorite (oxidation state +1), whereas the specified hot/concentrated conditions yield chlorate (oxidation state +5), testing knowledge of oxidation state extremes and reaction stoichiometry.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Redox Reactions - Class 11 Part 2 |
| Concept | Oxidation State Extremes |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |