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Question #44795
The Question
For a complex gas-phase reaction, the temperature dependence of the rate constant deviates from classical Arrhenius behavior and is accurately described by the modified equation , where , , and are temperature-independent constants. A student plots versus and observes a non-linear curve. By drawing tangents to the curve, the student determines the instantaneous apparent activation energy () to be at and at . Assuming ideal gas behavior, what are the values of the true threshold energy () and the temperature exponent ()? (Given: )
Options
- A.
- B.
- C.
- D.
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
Instantaneous vs. Average Rate|Arrhenius Pre-exponential Factor
Why This Question Is Tricky
Common Mistakes
This problem tests the 'Chemical Exception' of the temperature-dependent frequency factor in complex reactions.
Students often blindly apply the linear Arrhenius equation () and assume is a strict constant.
By introducing , the slope of vs becomes temperature-dependent.
Students failing to differentiate the modified Arrhenius equation will either assume or incorrectly apply standard Transition State Theory () without deriving the empirical from the provided instantaneous rates.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Chemical Kinetics - Class 12 |
| Concept | Instantaneous vs. Average Rate |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |