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Question #44768
The Question
During the discharge cycle of a secondary battery, a localized pH gradient alters the redox behavior of the electrolyte. To investigate this thermodynamic shift, a technician constructs the following concentration-dependent electrochemical cell at :
The technician observes that the cell potential is exactly , indicating that the indicator fails to spontaneously oxidize under these specific conditions.
Given:
Calculate the value of (the pH of the cathodic compartment).
Options
- A.
2.5
- B.
3.0
- C.
2.0
- D.
1.0
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
Secondary Battery Discharge Cycles|KMnO₄ Redox pH Dependency|E° (M³⁺/M²⁺) Redox Potential
Why This Question Is Tricky
Common Mistakes
This problem tests the Nernstian dependence of the redox couple on pH and concentration gradients.
The 'Hidden Variable' is the formal potential shift caused by non-standard states.
Students frequently fall into the trap of ignoring the reaction quotient and equating the standard potentials directly, which incorrectly yields .
Furthermore, it evaluates the correct application of stoichiometric coefficients as exponents in the Nernst equation, specifically the 8th power for and the 5-electron transfer, which are common points of failure.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Electrochemistry - Class 12 |
| Concept | Secondary Battery Discharge Cycles |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |