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Question #44160
The Question
Consider the complete dissociation of of \ce{O2(g)} into \ce{O(g)}. According to Molecular Orbital Theory (MOT), let be the number of unpaired electrons in an \ce{O2} molecule. Let be the number of unpaired electrons in an \ce{O} atom in its ground state.
A sample of of \ce{O2(g)} initially at and volume undergoes the following sequence of steps: Step 1: Reversible isothermal expansion to a volume such that the magnitude of work done is . Step 2: Complete dissociation into \ce{O(g)} at constant volume and constant temperature . Step 3: Reversible isothermal compression of the product gas back to the original volume .
Given the standard enthalpy of dissociation of \ce{O2(g)} at is . Assume ideal gas behavior for all species. (Use , )
Which of the following options correctly represents the net work done () and the net heat absorbed () by the system in the entire process? (Use standard IUPAC sign convention)
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
MOT and Magnetic Nature|Reversible Expansion Work|Enthalpy Definition
Why This Question Is Tricky
Common Mistakes
This problem tests the integration of Molecular Orbital Theory (MOT) with chemical thermodynamics.
The first trap is identifying the correct number of unpaired electrons in \ce{O2} using MOT () rather than a simple Lewis structure ().
The second trap is the conflation of and during the constant-volume dissociation step; students must subtract to find the correct internal energy change.
The final, most lethal trap is forgetting that the number of moles of gas has doubled () for the compression step, which directly affects the work calculation.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Chemical Bonding and Molecular Structure - Class 11 Part 1 |
| Concept | MOT and Magnetic Nature |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |