Exam 12: Infrared Spectroscopy

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1630-1820 cm^-1 (strong, broad) and 1000-1250 cm^-1; but does not have peaks at 3200-3650 cm^-1?

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Question 1

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Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of N,N-dimethylacetamide, CH₃CON(CH₃)₂, is higher than that of methyl acetate, CH₃CO₂CH₃.

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Question 2

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The C=O bond of the amide is weaker than that of the ester. Nitrogen is less electronegative than oxygen, and therefore a better electron pair donor. Accordingly, the resonance contributor in which the nitrogen has donated a pair of electrons to the carbonyl carbon atom is an important contributor to the structure.

Which of the following compounds gives an infrared spectrum with no significant peaks at ~3300 cm^-1 or 1600-1680 cm^-1?

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Question 3

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Which of the following compounds gives a carbonyl bond absorption at the lowest frequency?

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Question 4

Which of the following compounds gives an infrared spectrum with peaks at 3000-3500 cm^-1 and ~1750 cm^-1?

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Question 5

Which of the following regions in the electromagnetic spectrum corresponds to the radiation with the longest wavelength?

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Question 6

Which of the following processes takes place upon absorption of infrared radiation?

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Question 7

What range of wavelengths corresponds to the infrared region of the electromagnetic spectrum?

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Question 8

Which of the following compounds gives an infrared spectrum with peaks in the ranges of 3200-3650 (strong, broad) and 1600-1640 cm^-1 (medium); but does not have peaks at 1630-1820 (strong)?

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Question 9

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1000-1250 cm^-1 (strong), but does not have peaks 3200-3650 at 1630-1820 or cm^-1?

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Question 10

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C₅H₁₀O₂)?

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Question 11

Which of the following bonds gives rise to a strong, broad, absorbance at approximately 3200-3650 cm^-1 in the infrared spectrum?

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Question 12

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C₆H₁₄O)?

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Question 13

What are the units of wavenumber, , in infrared spectroscopy?

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Question 14

Which of the following bonds gives the weakest peak in the infrared spectrum for a stretching vibration?

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Question 15

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C₄H₉NO)?

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Question 16

Which of the following carbon-carbon bonds undergoes stretching at the highest frequency?

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Question 17

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of 2-butanone is higher than that of 3-buten-2-one.

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Question 18

Which of the following compounds gives an infrared spectrum with peaks at 3300 cm^-1 (sharp peak) and 2150 cm^-1 (sharp peak)?

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Question 19

Provide the structure of three compounds with the molecular formula C₄H₈O that give an absorption peak at 1600-1640 cm^-1 in the infrared spectrum, but no significant peaks at 3000-3600 cm^-1 or at 1650-1750 cm^-1.

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Question 20

Showing 1 - 20 of 44

Exam 12: Infrared Spectroscopy

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1630-1820 cm-1 (strong, broad) and 1000-1250 cm-1; but does not have peaks at 3200-3650 cm-1?

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of N,N-dimethylacetamide, CH3CON(CH3)2, is higher than that of methyl acetate, CH3CO2CH3.

Which of the following compounds gives an infrared spectrum with no significant peaks at ~3300 cm-1 or 1600-1680 cm-1?

Which of the following compounds gives a carbonyl bond absorption at the lowest frequency?

Which of the following compounds gives an infrared spectrum with peaks at 3000-3500 cm-1 and ~1750 cm-1?

Which of the following regions in the electromagnetic spectrum corresponds to the radiation with the longest wavelength?

Which of the following processes takes place upon absorption of infrared radiation?

What range of wavelengths corresponds to the infrared region of the electromagnetic spectrum?

Which of the following compounds gives an infrared spectrum with peaks in the ranges of 3200-3650 (strong, broad) and 1600-1640 cm-1 (medium); but does not have peaks at 1630-1820 (strong)?

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1000-1250 cm-1 (strong), but does not have peaks 3200-3650 at 1630-1820 or cm-1?

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C5H10O2)?

Which of the following bonds gives rise to a strong, broad, absorbance at approximately 3200-3650 cm-1 in the infrared spectrum?

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C6H14O)?

What are the units of wavenumber, , in infrared spectroscopy?

Which of the following bonds gives the weakest peak in the infrared spectrum for a stretching vibration?

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C4H9NO)?

Which of the following carbon-carbon bonds undergoes stretching at the highest frequency?

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of 2-butanone is higher than that of 3-buten-2-one.

Which of the following compounds gives an infrared spectrum with peaks at 3300 cm-1 (sharp peak) and 2150 cm-1 (sharp peak)?

Provide the structure of three compounds with the molecular formula C4H8O that give an absorption peak at 1600-1640 cm-1 in the infrared spectrum, but no significant peaks at 3000-3600 cm-1 or at 1650-1750 cm-1.

Covalent Bonding and Shapes of Molecules

Alkanes and Cycloalkanes

Stereoisomerism and Chirality

Acids and Bases

Alkenes: Bonding, Nomenclature, and Properties

Reactions of Alkenes

Alkynes

Haloalkanes, Halogenation, and Radical Reactions

Nucleophilic Substitution and Beta-Elimination

Alcohols

Ethers, Epoxides, and Sulfides

Nuclear Magnetic Resonance Spectroscopy

Mass Spectrometry

An Introduction to Organometallic Compounds

Aldehydes and Ketones

Carboxylic Acids

Functional Derivatives of Carboxylic Acids

Enolate Anions and Enamines

Dienes, Conjugated Systems, and Pericyclic Reactions

Benzene and the Concept of Aromaticity

Reactions of Benzene and Its Derivatives

Filters

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1630-1820 cm^-1 (strong, broad) and 1000-1250 cm^-1; but does not have peaks at 3200-3650 cm^-1?

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of N,N-dimethylacetamide, CH₃CON(CH₃)₂, is higher than that of methyl acetate, CH₃CO₂CH₃.

Which of the following compounds gives an infrared spectrum with no significant peaks at ~3300 cm^-1 or 1600-1680 cm^-1?

Which of the following compounds gives an infrared spectrum with peaks at 3000-3500 cm^-1 and ~1750 cm^-1?

Which of the following compounds gives an infrared spectrum with peaks in the ranges of 3200-3650 (strong, broad) and 1600-1640 cm^-1 (medium); but does not have peaks at 1630-1820 (strong)?

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1000-1250 cm^-1 (strong), but does not have peaks 3200-3650 at 1630-1820 or cm^-1?

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C₅H₁₀O₂)?

Which of the following bonds gives rise to a strong, broad, absorbance at approximately 3200-3650 cm^-1 in the infrared spectrum?

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C₆H₁₄O)?

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C₄H₉NO)?

Which of the following compounds gives an infrared spectrum with peaks at 3300 cm^-1 (sharp peak) and 2150 cm^-1 (sharp peak)?

Provide the structure of three compounds with the molecular formula C₄H₈O that give an absorption peak at 1600-1640 cm^-1 in the infrared spectrum, but no significant peaks at 3000-3600 cm^-1 or at 1650-1750 cm^-1.