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

3. Acids and Bases

Organic Chemistry Reactions

Organic Chemistry

3. Acids and Bases

Organic Chemistry Reactions

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Multiple Choice

Which of the following dyes is used first in an acid-fast stain?

Carbol fuchsin

Safranin

Methylene blue

Crystal violet

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Verified step by step guidance

Understand the purpose of an acid-fast stain: It is a differential staining technique used to identify acid-fast organisms, such as Mycobacterium species, which have waxy cell walls that are not easily penetrated by standard stains.

Identify the primary stain used in the acid-fast staining process: The primary stain is the dye that initially colors the cells. In the acid-fast stain, this is crucial for penetrating the waxy cell wall.

Recognize the role of Carbol fuchsin: Carbol fuchsin is a phenolic compound that is lipid-soluble, allowing it to penetrate the waxy cell walls of acid-fast bacteria, making it the primary stain in this process.

Consider the other dyes listed: Safranin, Methylene blue, and Crystal violet are not used as the primary stain in the acid-fast staining technique. They serve different purposes in other staining methods.

Conclude that Carbol fuchsin is the dye used first in an acid-fast stain, as it is specifically designed to penetrate and stain the waxy cell walls of acid-fast bacteria.