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

28. Carbohydrates

Monosaccharides - Weak Oxidation (Aldonic Acid)

Organic Chemistry

28. Carbohydrates

Monosaccharides - Weak Oxidation (Aldonic Acid)

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1:27 minutes

Problem 34b

Textbook Question

What product or products are obtained when D-galactose reacts with each of the following?
b. Ag⁺, NH₃, HO^-

Verified step by step guidance

Identify the functional groups present in d-galactose. D-galactose is an aldose sugar, meaning it contains an aldehyde group (-CHO) at the anomeric carbon and multiple hydroxyl (-OH) groups.

Understand the reaction conditions. The reagents Ag+, NH3, and HO- together form Tollens' reagent, which is commonly used to oxidize aldehydes to carboxylic acids.

Recognize the specific reaction mechanism. Tollens' reagent oxidizes the aldehyde group (-CHO) in d-galactose to a carboxylate group (-COO⁻), forming the corresponding aldonic acid (in this case, d-galactonic acid).

Write the chemical equation for the reaction. The aldehyde group of d-galactose reacts with Tollens' reagent, resulting in the formation of d-galactonic acid and the reduction of Ag+ to metallic silver (Ag⁰).

Conclude that the product of this reaction is d-galactonic acid, and metallic silver is deposited as a byproduct. The hydroxyl groups on the sugar remain unchanged during this reaction.

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Key Concepts

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

D-Galactose Structure

D-galactose is a monosaccharide with an aldehyde group and multiple hydroxyl groups. It is an aldohexose, meaning it contains six carbon atoms and an aldehyde functional group at one end. Understanding its structure is crucial for predicting its reactivity in chemical reactions, particularly in oxidation and reduction processes.

Oxidation-Reduction Reactions

In organic chemistry, oxidation-reduction (redox) reactions involve the transfer of electrons between species. In the context of D-galactose reacting with Ag+ (silver ion), the aldehyde group can be oxidized to a carboxylic acid, while Ag+ is reduced to metallic silver. This transformation is essential for understanding the products formed in the reaction.

Complex Formation with Ammonia

Ammonia (NH3) can react with carbonyl compounds, such as the aldehyde in D-galactose, to form imines or amines. This reaction is significant in organic synthesis and can lead to the formation of various nitrogen-containing products. Recognizing how ammonia interacts with sugars is key to predicting the outcome of the reaction in question.

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