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

In the context of organic chemistry reactions, why is Gram's iodine added to a slide during a starch test?

To act as a catalyst for the reaction

To neutralize the pH of the solution

To enhance the visibility of starch by forming a blue-black complex

To dissolve non-polar compounds

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Verified step by step guidance

Understand the purpose of the starch test: The starch test is used to detect the presence of starch in a sample. Starch is a polysaccharide composed of glucose units and is commonly found in plants.

Recognize the role of iodine in the test: Gram's iodine is added to the sample because it interacts with the starch molecules. Specifically, iodine forms a complex with the helical structure of amylose, a component of starch.

Describe the visual change: When iodine interacts with starch, it forms a blue-black complex. This color change is a visual indicator of the presence of starch in the sample.

Clarify why iodine is not a catalyst: In this context, iodine does not act as a catalyst. A catalyst is a substance that increases the rate of a chemical reaction without being consumed. Here, iodine's role is purely to enhance visibility.

Explain why iodine does not neutralize pH or dissolve non-polar compounds: Iodine does not affect the pH of the solution nor does it dissolve non-polar compounds in this test. Its primary function is to form a visible complex with starch.