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

21. Aldehydes and Ketones: Nucleophilic Addition

Imine vs Enamine

Organic Chemistry

21. Aldehydes and Ketones: Nucleophilic Addition

Imine vs Enamine

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2:42 minutes

Problem 37

Textbook Question

Which ketone forms the most hydrate in an aqueous solution?

Verified step by step guidance

Step 1: Understand the concept of hydrate formation. Hydrate formation occurs when a ketone reacts with water to form a geminal diol. The extent of hydrate formation depends on the electronic and steric effects of substituents attached to the ketone.

Step 2: Analyze the structures of ketones A and B. Ketone A has two electron-withdrawing nitro groups (-NO2) attached to the ring, while ketone B has two alkyl groups attached to the ring.

Step 3: Consider the effect of electron-withdrawing groups. Electron-withdrawing groups like -NO2 increase the electrophilicity of the carbonyl carbon, making it more reactive toward water and favoring hydrate formation.

Step 4: Compare steric effects. Ketone B has alkyl groups, which are bulkier and can hinder the approach of water to the carbonyl carbon, reducing the likelihood of hydrate formation.

Step 5: Conclude that ketone A, with its electron-withdrawing nitro groups, forms the most hydrate in an aqueous solution due to increased electrophilicity and reduced steric hindrance compared to ketone B.

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Key Concepts

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

Hydration of Ketones

Hydration of ketones refers to the reaction where a ketone reacts with water to form a hydrate, which is a geminal diol. The extent of hydration depends on the stability of the resulting hydrate and the steric and electronic effects of substituents on the ketone. More stable hydrates are favored in aqueous solutions.

Electronic Effects

Electronic effects, such as inductive and resonance effects, influence the reactivity of ketones. Electron-withdrawing groups, like nitro groups, can stabilize the positive charge that develops during the formation of the hydrate, thus enhancing the hydration process. Understanding these effects is crucial for predicting which ketone will form more hydrate.

Steric Hindrance

Steric hindrance refers to the repulsion between bulky groups that can impede reactions. In the context of ketones, if a ketone has large substituents near the carbonyl group, it may hinder the approach of water molecules, reducing the formation of the hydrate. Evaluating steric factors is essential for determining the most reactive ketone in hydration.

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