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

4. Alkanes and Cycloalkanes

Naming Alkenes

Organic Chemistry

4. Alkanes and Cycloalkanes

Naming Alkenes

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4:07 minutes

Problem 8a

Textbook Question

a. How many vinylic hydrogens does cyclopentene have?
b. How many allylic hydrogens does it have?

Verified step by step guidance

Step 1: Understand the definitions of vinylic and allylic hydrogens. Vinylic hydrogens are directly attached to a carbon-carbon double bond (sp² hybridized carbons). Allylic hydrogens are attached to a carbon atom that is adjacent to a carbon-carbon double bond (sp³ hybridized carbons).

Step 2: Draw the structure of cyclopentene. Cyclopentene is a five-membered ring with one double bond. Place the double bond in the ring and label the carbons for clarity.

Step 3: Identify the vinylic hydrogens. Look at the two carbons involved in the double bond. Each of these carbons is sp² hybridized. Count the hydrogens directly attached to these two carbons.

Step 4: Identify the allylic hydrogens. Look at the carbons adjacent to the double bond. These carbons are sp³ hybridized. Count the hydrogens attached to these adjacent carbons.

Step 5: Sum up the vinylic and allylic hydrogens separately. Ensure that you account for all hydrogens in the structure and verify your counts to avoid errors.

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Key Concepts

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

Vinylic Hydrogens

Vinylic hydrogens are the hydrogen atoms that are directly bonded to a carbon-carbon double bond (C=C). In the case of cyclopentene, which contains a double bond in its ring structure, the hydrogens attached to the carbons involved in the double bond are considered vinylic. Understanding the structure of cyclopentene is essential to identify these hydrogens accurately.

Allylic Hydrogens

Allylic hydrogens are those that are attached to a carbon atom adjacent to a carbon-carbon double bond. In cyclopentene, the carbons next to the double bond contribute to the count of allylic hydrogens. Recognizing the position of the double bond in the cyclopentene structure helps in determining how many allylic hydrogens are present.

Cyclopentene Structure

Cyclopentene is a cyclic alkene with five carbon atoms and one double bond. Its structure influences the number of vinylic and allylic hydrogens. By visualizing or drawing the molecular structure, one can easily identify the locations of the double bond and the corresponding hydrogens, which is crucial for answering the question about the number of vinylic and allylic hydrogens.

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