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

15. Analytical Techniques:IR, NMR, Mass Spect

Mass Spect:Fragmentation

Organic Chemistry

15. Analytical Techniques:IR, NMR, Mass Spect

Mass Spect:Fragmentation

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Multiple Choice

Which of the following is NOT expected to be a major peak in the mass spectrum for the given molecule?

43 amu

165 amu

91 amu

184

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Identify the molecular structure of the given compound. The structure shows a benzene ring attached to a two-carbon chain with a chlorine atom and a carbonyl group (C=O).

Calculate the molecular weight of the compound. Add the atomic masses of all the atoms in the molecule: C9H9ClO. Use the approximate atomic masses: C=12, H=1, Cl=35.5, O=16.

Consider common fragmentation patterns in mass spectrometry. The benzyl cation (C7H7+) is a common fragment with a mass of 91 amu, and the loss of a chlorine atom (Cl) from the molecular ion is also common.

Evaluate the given mass values (43 amu, 91 amu, 165 amu, 184 amu) against the calculated molecular weight and common fragments. Determine which mass is not a typical fragment or the molecular ion.

Conclude that 165 amu is not expected to be a major peak, as it does not correspond to the molecular ion or a common fragment of the given structure.