Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

6. Thermodynamics and Kinetics

Carbocation Stability

Organic Chemistry

6. Thermodynamics and Kinetics

Carbocation Stability

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5:06 minutes

Problem 86e

Textbook Question

Which species in each pair is more stable?
e.

Verified step by step guidance

Step 1: Understand the concept of carbocation stability. Carbocations are positively charged carbon species, and their stability is influenced by factors such as hyperconjugation, resonance, and inductive effects. More stable carbocations are better stabilized by these factors.

Step 2: Analyze the first pair (C+H2CH2CH═CH2 vs. CH3C+HCH═CH2). For C+H2CH2CH═CH2, the carbocation is located on a primary carbon, and there is no resonance stabilization. For CH3C+HCH═CH2, the carbocation is located on a secondary carbon, and it can be stabilized by resonance with the adjacent double bond.

Step 3: Apply resonance stabilization to CH3C+HCH═CH2. The positive charge on the secondary carbon can delocalize into the π-electrons of the double bond, forming resonance structures. This delocalization increases the stability of the carbocation.

Step 4: Compare the stability of the two species in the first pair. CH3C+HCH═CH2 is more stable due to resonance stabilization and the fact that it is a secondary carbocation, which is inherently more stable than a primary carbocation.

Step 5: For part g, additional information is needed to analyze the stability of the species. If you provide the missing details, I can guide you through the solution effectively.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Carbocation Stability

Carbocation stability is influenced by the degree of substitution and the presence of electron-donating groups. Tertiary carbocations are more stable than secondary, which are more stable than primary due to hyperconjugation and inductive effects. In the given pairs, analyzing the structure and substitution of the carbocations helps determine which is more stable.

Resonance Effects

Resonance refers to the delocalization of electrons across adjacent bonds, which can stabilize a molecule. Carbocations can be stabilized by resonance if they are adjacent to double bonds or lone pairs. This effect can significantly influence the stability of the carbocations in the question, as resonance can distribute the positive charge over a larger area.

Hybridization and Geometry

The hybridization of the carbon atom bearing the positive charge affects the stability of carbocations. sp2 hybridized carbocations (trigonal planar geometry) are generally more stable than sp3 hybridized ones (tetrahedral geometry) due to better orbital overlap and less steric strain. Understanding the hybridization of the carbons in the given structures is crucial for assessing their stability.

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Which species in each pair is more stable?e.

Key Concepts

Carbocation Stability

Resonance Effects

Hybridization and Geometry

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Which species in each pair is more stable?
e.