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

IR Spect:Drawing Spectra

Organic Chemistry

15. Analytical Techniques:IR, NMR, Mass Spect

IR Spect:Drawing Spectra

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Problem 13d

Textbook Question

Given the IR spectrum, suggest what functional groups might correspond to the given molecular formula.
(d) C₇H₅O
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Verified step by step guidance

Start by analyzing the molecular formula C₇H₅O. Calculate the degree of unsaturation using the formula: \( ext{Degree of Unsaturation} = rac{2C + 2 + N - H - X}{2} \), where C is the number of carbons, N is the number of nitrogens, H is the number of hydrogens, and X is the number of halogens. For C₇H₅O, this calculation will help determine the number of rings and/or double bonds.

Examine the IR spectrum for key absorption bands. Look for a strong peak around 1700 cm⁻¹, which is indicative of a carbonyl group (C=O). This is a common functional group in organic molecules containing oxygen.

Identify any peaks in the region of 3000-3100 cm⁻¹, which could suggest the presence of aromatic C-H stretches. This is consistent with the presence of an aromatic ring, which is likely given the degree of unsaturation calculated earlier.

Check for any peaks around 1600 cm⁻¹ and 1500 cm⁻¹, which are characteristic of C=C stretches in aromatic rings. These peaks further support the presence of an aromatic ring in the structure.

Consider the possibility of other functional groups based on the IR spectrum. If there are no significant peaks in the region of 3200-3600 cm⁻¹, it is unlikely that there are hydroxyl groups (O-H) present. Use the combination of the IR data and the molecular formula to hypothesize the structure, likely involving an aromatic ring with a carbonyl group.

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Key Concepts

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

Infrared (IR) Spectroscopy

IR spectroscopy is a technique used to identify functional groups in a molecule by measuring the absorption of infrared light at different wavelengths. Each functional group has a characteristic absorption range, allowing for the identification of specific bonds and structures within a compound.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. Common functional groups include hydroxyl, carbonyl, and aromatic rings, each with distinct IR absorption patterns that help in identifying them in a spectrum.

Molecular Formula Analysis

Analyzing a molecular formula involves determining the possible structures and functional groups that fit the given formula. For C₇H₅O, one might consider aromatic compounds like benzaldehyde, which includes an aromatic ring and a carbonyl group, both detectable via IR spectroscopy.

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Textbook Question

Each of the IR spectra shown below is the spectrum of one of the following compounds. Identify the compound that produced each spectrum.

b. <IMAGE>

Textbook Question

Match each of the four IR spectra to one of the given compounds. [One of the compounds does not match a spectrum.]

(d) <IMAGE>

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Match each of the four IR spectra to one of the given compounds. [One of the compounds does not match a spectrum.]

Textbook Question

What functional groups might be present in the IR spectra for the molecules with the given molecular formulas. [Be sure to use the molecular formula in your analysis.]

(b) C₃H₄O₄

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Hoping to make the following diene, a chemist treated the diol shown with acid. Based on the IR spectrum, was the reaction successful? If not, what compound was made instead?

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Textbook Question

What functional groups are present in a molecule with a molecular formula of C₄H₁₀O and the following IR spectrum? [Use Table 14.2 for this.]

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On a day in which the laboratory air conditioning stopped working, a chemist hypothesized that the atmosphere would provide enough ambient heat to drive the nitrile hydrolysis reaction to the carboxylic acid. Based on the IR of the resulting product, was this hypothesis correct?

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Textbook Question

Given the IR spectrum, suggest what functional groups might correspond to the given molecular formula.

(b) C₃H₇NO

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