Complete Test Bank | Infrared Spectroscopy And Mass – Ch.14

Organic Chemistry, 4e (Klein)

Chapter 14 Infrared Spectroscopy and Mass Spectrometry

1) Which of the statements given is not true about electromagnetic radiation?

A) frequency is directly proportional to wavelength

B) frequency is directly proportional to energy

C) frequency is inversely proportional to wavelength

D) wavelength is inversely proportional to energy

E) energy is directly proportional to frequency and wavelength

Diff: 1

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

2) Which of the types of electromagnetic radiation shown has the highest energy?

A) UV

B) X-ray

C) IR

D) microwave

E) visible

Diff: 1

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

3) Which of the types of electromagnetic radiation shown has the longest wavelength?

A) UV

B) X-ray

C) IR

D) microwave

E) visible

Diff: 1

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

4) Which of the types of electromagnetic radiation shown has the highest frequency?

A) UV

B) X-ray

C) IR

D) microwave

E) visible

Diff: 1

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

5) Arrange the given types of electromagnetic radiation in decreasing order of frequency (from highest frequency to lowest frequency).

A) V > III > IV > II > I

B) II > V > III > IV > I

C) I > IV > III > V > II

D) V > II > IV > III > I

E) II > IV > V > III > I

Diff: 2

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

6) Arrange the given types of electromagnetic radiation in decreasing order of wavelength (from highest to lowest wavelength).

A) V > III > IV > II > I

B) II > V > III > IV > I

C) I > IV > III > V > II

D) V > II > IV > III > I

E) II > IV > V > III > I

Diff: 2

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

7) Which of the information shown is primarily obtained from infrared spectroscopy?

A) arrangement of carbon and hydrogen atoms in a compound

B) molecular weight of a compound

C) any conjugated π system present in a compound

D) functional groups present in a compound

E) all of these

Diff: 1

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

8) Which of the information shown is primarily obtained from nuclear magnetic resonance spectroscopy?

A) arrangement of carbon and hydrogen atoms in a compound

B) molecular weight of a compound

C) any conjugated π system present in a compound

D) functional groups present in a compound

E) all of these

Diff: 1

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

9) Which of the information shown is primarily obtained from UV-VIS spectroscopy?

A) arrangement of carbon and hydrogen atoms in a compound

B) molecular weight of a compound

C) any conjugated π system present in a compound

D) functional groups present in a compound

E) all of these

Diff: 1

Learning Objective: 14.1 Describe the wave-like and particle-like nature of electromagnetic radiation, and define photon, ΔE, and vibrational excitation

10) Absorption of ________ radiation results in vibrational excitation of the bonds in a compound.

A) UV

B) Microwave

C) IR

D) Visible

E) x-ray

Diff: 1

Learning Objective: 14.2 Discuss the nature of the chemical analysis that can be accomplished with IR spectroscopy and describe how this is accomplished

11) Which of the given vibrations are observed in IR spectroscopy?

A) stretching

B) rotational

C) bending

D) A and B

E) A and C

Diff: 1

Learning Objective: 14.2 Discuss the nature of the chemical analysis that can be accomplished with IR spectroscopy and describe how this is accomplished

12) Which of the given characteristics is currently most often used to indicate the location of a signal on an IR spectrum?

A) wavelength

B) wavenumber

C) frequency

D) A and B

E) all of these

Diff: 1

Learning Objective: 14.2 Discuss the nature of the chemical analysis that can be accomplished with IR spectroscopy and describe how this is accomplished

13) An object that feels warm is emitting ________ amounts of infrared radiation than an object that feels cool.

A) greater

B) lower

C) more variable

D) less intense

Diff: 1

Learning Objective: 14.2 Discuss the nature of the chemical analysis that can be accomplished with IR spectroscopy and describe how this is accomplished

14) Which of the choices given are units for wavenumber in IR spectroscopy?

A) cm-1

B) cm

C) J·s-1

D) mm

E) J·s

Diff: 1

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

15) Which of the wavenumbers given corresponds to the C=O double bond region on an IR spectrum?

A) 1500 — 4000 cm-1

B) 400 — 4000 cm-1

C) 400 — 1500 cm-1

D) 2100 — 2300 cm-1

E) 1600 — 1850 cm-1

Diff: 1

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

16) Which of the wavenumbers given corresponds to the carbon/carbon triple bond region on an IR spectrum?

A) 1500 — 4000 cm-1

B) 400 — 4000 cm-1

C) 400 — 1500 cm-1

D) 2100 — 2300 cm-1

E) 1600 — 1850 cm-1

Diff: 1

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

17) Which of the wavenumbers given corresponds to the fingerprint region on an IR spectrum?

A) 1500 — 4000 cm-1

B) 400 — 4000 cm-1

C) 400 — 1500 cm-1

D) 2100 — 2300 cm-1

E) 1600 — 1850 cm-1

Diff: 1

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

18) Which of the given statement(s) is(are) true about the frequency of a stretching vibration according to Hooke's law?

A) it is directly proportional to strength of the bond and the reduced mass

B) it is inversely proportional to strength of the bond and the reduced mass

C) it is directly proportional to strength of the bond and inversely proportional to the reduced mass

D) it is inversely proportional to the strength of the bond and proportional to the reduced mass

E) it is not related to either the strength of the bond or the reduced mass

Diff: 2

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

19) Rank the infrared absorption of the indicated bonds in order of decreasing wavenumber (from highest to lowest wavenumber).

A) III > II > I

B) I > II > III

C) II > I > III

D) III > I > II

E) II > III > I

Diff: 1

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

20) Rank absorption of the indicated bonds in order of decreasing wavenumber (from highest to lowest wavenumber).

A) III > II > I

B) I > II > III

C) II > I > III

D) III > I > II

E) II > III > I

Diff: 1

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

21) Rank absorption of the indicated bonds in order of decreasing wavenumber (from highest to lowest wavenumber).

A) III > II > I

B) I > II > III

C) II > I > III

D) III > I > II

E) II > III > I

Diff: 1

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

22) Which of the given compounds has the lowest wavenumber for its carbonyl absorption?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

23) Which one of the given compounds has the lowest wavenumber for its carbonyl absorption?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

24) Which one of the given compounds has the highest wavenumber for its C=C absorption?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

25) Which of the given compounds has the highest wavenumber for its carbonyl absorption?

A) I

B) II

C) III

D) II and III

Diff: 3

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

26) Rank absorption of the indicated bonds in decreasing order of wavenumber (from highest to lowest wavenumber).

A) I > V > II > IV > III

B) IV > II > I > V > III

C) II > I > V > III > IV

D) IV > I > V > II > III

E) IV > II > V > I > III

Diff: 2

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

27) Why is the expected stretching absorption of the C=O bond 1685 cm-1 for the structure I and 1715 cm-1 for structure II?

A) Having fewer double bonds results in lowering of all of the stretching absorptions.

B) The C to O double bond of compound I has greater single bond character than the C to O double bond of compound II.

C) The expected stretching absorption is lowered in all molecules with cyclohexane rings.

D) Compound I lacks conjugation, which is present in compound II.

E) Compound II has a C to O double bond with considerable single bond character, lowering the expected stretching absorption.

Diff: 3

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

28) Why does the expected stretching absorption of the C=O bond in compounds I and II differ, as shown below?

A) Only compound I has resonance, causing it to have a higher stretching absorption.

B) Only compound II has resonance, causing it to have a higher stretching absorption.

C) Compound II has more possible resonance structures, increasing the single bond character of the carbonyl group.

D) Compound I has more possible resonance structures, increasing the single bond character of the carbonyl group.

E) Compound I has a C to O bond with more single bond character than that of compound II, increasing the expected stretching absorption of the bond.

Diff: 3

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

29) The C–O absorption in carboxylic acids appears around 1250 cm-1. The C–O absorption in an alcohol appears around 1050 cm-1. Explain why.

A) Only compound I has resonance, causing it to have a higher stretching absorption.

B) Only compound II has resonance, causing it to have a higher stretching absorption.

C) Compound II has more possible resonance structures, increasing the single bond character of the carbonyl group.

D) Compound I has more possible resonance structures, increasing the single bond character of the carbonyl group.

E) Compound I has a C to O bond with more single bond character than that of compound II, increasing the expected stretching absorption of the bond.

Diff: 3

Learning Objective: 14.3 Describe the factors that determine wavenumber, and then describe what can be learned from the signals in the diagnostic region and the fingerprint region of the IR spectrum

30) Which of the given statement(s) is(are) true for an IR-active bond?

A) the bond must be symmetrical

B) a vibration must result in a change of bond length

C) a vibration must result in a change of bond angle

D) a vibration must result in a change of bond dipole

E) a vibration must result in a change of isotope

Diff: 2

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

31) Which of the bonds shown has the weakest absorption?

A) I

B) II

C) III

D) I and IV

E) I and III

Diff: 2

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

32) Which of the bonds shown has the weakest absorption?

A) C=C

B) O–H

C) C=O

D) sp3 C–H

E) A and D

Diff: 2

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

33) Which of the bonds shown has the strongest absorption?

A) C=N

B) C≡C

C) C=O

D) sp2 C–H

E) C–O

Diff: 2

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

34) 3-Hexyne does not show absorption in the range of 2000-2200 cm-1, whereas 1-hexyne does. What is a reasonable explanation for 3-hexyne's absence of absorption?

A) it is a symmetrical compound

B) there is no change in bond dipole

C) there is no bond dipole

D) it is an unsymmetrical compound

E) A, B and C

Diff: 2

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

35) Which of the alkene shown groups produces the strongest signal in an IR spectrum?

A) I

B) II

C) III

D) IV

Diff: 2

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

36) Which of the alkene groups shown produces the stronger signal in an IR spectrum? Explain why.

A) Yes, compound I produces a stronger signal because fluorine is more electronegative than chlorine and produces a larger dipole moment.

B) Yes, compound II produces a stronger signal because chlorine is more electronegative than chlorine and produces a larger dipole moment.

C) No, the alkene groups produces similar signals because their structures are so similar.

D) No, the alkene groups produce similar signals because both have vinylic halogen atoms.

Diff: 3

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

37) Will one of the alkene groups shown produce a stronger signal in an IR spectrum?

A) Yes, compound I produces a stronger signal because it has a larger dipole moment.

B) Yes, compound II produces a stronger signal because it has a larger dipole moment.

C) No, the alkene groups produce similar signals because they have similar double bonds.

D) No, the alkene groups produce similar signals because they both contain fluorine.

Diff: 3

Learning Objective: 14.4 Discuss the factors that determine the strength of the signal in an IR spectrum and which bonds produce strong signals and which produce weaker ones

38) Diluted alcohols show a ________ absorption around 3600 cm-1, due to ________.

A) sharp, hydrogen bonding

B) broad, hydrogen bonding

C) sharp, absence of hydrogen bonding

D) broad, absence of hydrogen bonding

Diff: 2

Learning Objective: 14.5 Discuss the shape of signals from alcohols and amines

39) Concentrated alcohols show a ________ absorption in the region of 3200-3600 cm-1 due to ________.

A) sharp, hydrogen bonding

B) broad, hydrogen bonding

C) sharp, polarity

D) broad, polarity

Diff: 2

Learning Objective: 14.5 Discuss the shape of signals from alcohols and amines

40) Carboxylic acids show a very broad absorption for the OH group compared to alcohols because they can form a ________.

A) dimer

B) polymer

C) trimer

D) tetramer

Diff: 2

Learning Objective: 14.5 Discuss the shape of signals from alcohols and amines

41) Primary amines show two medium absorption bands around 3400 cm-1 due to ________.

A) symmetric stretching

B) asymmetric stretching

C) both symmetric and asymmetric stretching

D) hydrogen bonding

Diff: 2

Learning Objective: 14.5 Discuss the shape of signals from alcohols and amines

42) How can you distinguish between cyclohexanol and cyclohexanecarboxylic acid using IR spectroscopy?

A) Cyclohexanecarboxylic acid shows a broader OH absorption associated with its carboxylic acid compared with the narrower OH absorption for the alcohol of cyclohexanol.

B) Cyclohexanol shows a carbonyl absorption that will not be present in cyclohexanecarboxylic acid.

C) Cyclohexanecarboxylic acid shows a carbonyl absorption that is not be present in cyclohexanol.

D) A and B

E) A and C

Diff: 2

Learning Objective: 14.5 Discuss the shape of signals from alcohols and amines

43) Determine whether each of the IR spectra given is consistent with the structure of an alcohol, a ketone, an aldehyde, a carboxylic acid, a primary amine, or a secondary amine.

I.

SDBS: National Institute of Advanced Industrial Science and Technology

II.

SDBS: National Institute of Advanced Industrial Science and Technology

A) Spectrum I is consistent with an aldehyde and spectrum II is consistent with an alcohol.

B) Spectrum II is consistent with an aldehyde and spectrum II is consistent with an alcohol.

C) Spectrum I is consistent with a primary amine and spectrum II is consistent with a secondary amine.

D) Spectrum I is consistent with a ketone and spectrum II is consistent with a carboxylic acid.

E) Spectrum I is consistent with a carboxylic acid and spectrum II is consistent with a primary amine.

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

44) Determine whether each of the IR spectra given is consistent with the structure of an alcohol, a ketone, an aldehyde, a carboxylic acid, a primary amine, a secondary amine, a primary amide, or a secondary amide.

I.

SDBS: National Institute of Advanced Industrial Science and Technology

II.

A) Spectrum I is consistent with a carboxylic acid and spectrum II is consistent with an alcohol.

B) Spectrum II is consistent with a primary amine and spectrum II is consistent with a secondary amine.

C) Spectrum I is consistent with a primary amide and spectrum II is consistent with a ketone.

D) Spectrum I is consistent with a secondary amide and spectrum II is consistent with a ketone.

E) Spectrum I is consistent with an aldehyde and spectrum II is consistent with a ketone.

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

45) Which of the given compounds shows a broad absorption near 3300 cm-1 and a sharp absorption at 1650 cm-1?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

46) Which of the given compounds shows two sharp absorptions, one at 3300 cm-1 and one at 2150 cm-1?

A) I

B) II

C) III

D) IV

E) none of these

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

47) Which of the given compounds shows two absorptions, one at 2700 cm-1 and one at 2800 cm-1, in addition to the carbonyl absorption?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

48) Which of the given compounds shows an absorption at 2250 cm-1?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

49) Which of the given compounds has have the lowest wavenumber for the carbonyl absorption?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

50) Which statement accurately describes the IR spectrum of the compound shown?

A) absorptions at 1720 cm-1 and 2150 cm-1

B) absorptions at 1800 cm-1 and 2150 cm-1

C) absorptions at 1720 cm-1 and 2250 cm-1

D) absorptions at 1800 cm-1 and 2250 cm-1

E) absorptions at 1650 cm-1 and 2150 cm-1

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

51) Which of the compounds give shows absorptions at 1640 cm-1, 2950 cm-1 and 3050 cm-1 on the IR spectrum?

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

52) What is a possible structure for a compound with molecular formula C6H10O that shows absorptions at 1720 cm-1 and at 2980 cm-1 on the IR spectrum?

A) I

B) II

C) III

D) I and II

E) I, II, and III

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

53) A compound with molecular formula C3H9N, shows absorptions at 3400 cm-1 (two), 2980 cm-1 and at 1100 cm-1 on the IR spectrum. Propose a possible structure for this compound.

A) CH3CH2CH2NH2

B) (CH3)2CHNH2

C) CH3NHCH2CH3

D) A and B

E) A and C

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

54) A compound with molecular formula C4H8O2, shows absorptions at 2500-3300 cm-1 (broad), 1720 cm-1 and at 1200 cm-1 on the IR spectrum. Propose a possible structure for this compound.

A) I

B) II

C) III

D) I and II

E) II and III

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

55) Which of the compounds shown has the highest wavenumber for carbonyl absorption?

A) I

B) II

C) III

D) IV

Diff: 3

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

56) Which of the compounds shown has absorptions at 1735 cm-1 and 1320 cm-1?

A) I

B) II

C) III

D) IV

E) V

Diff: 3

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

57) Which one of the given compounds has a structure consistent with the IR spectrum shown?

SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

58) Which one of the given compounds has a structure consistent with the IR spectrum shown?

SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

59) Which one of the given compounds has a structure consistent with the IR spectrum shown?

SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

60) Which one of the given compounds is consistent with the IR spectrum shown?

SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

61) Which one of the given compounds has a structure consistent with the IR spectrum shown?

SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

62) Which one of the given compounds has a structure is consistent with the IR spectrum shown?

SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

63) Which one of the given compounds is consistent with the following IR spectrum?

SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

64) For the given reaction, which of the following change(s) in the IR spectrum is consistent with conversion of the reactant to the product?

A) absorption at 2250 cm-1 should disappear

B) absorption at 3200-3400 cm-1 and 1720cm-1 should appear

C) absorption at 2250 cm-1 should disappear, new absorptions at 2600-2800 cm-1 and 1720 cm-1 should appear

D) absorption at 2250 cm-1 should disappear, a new absorption around 3400 cm-1 should appear

E) none of these

Diff: 2

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

65) For the given reaction, which of the following change(s) in the IR spectrum is consistent with conversion of the reactant to the product?

A) absorption at 2150 cm-1 should disappear

B) absorption at 3300 cm-1 and 2150 cm-1 should disappear

C) absorption at 2250 cm-1 should disappear, a new absorption at 3300 cm-1 should appear

D) absorption at 1650 cm-1 should disappear, a new absorption at 3300 cm-1 should appear

E) absorption at 3300 cm-1 and 2150 cm-1 should disappear, a new absorption at 1720 cm-1 should appear

Diff: 2

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

66) For the given reaction, which of the following change(s) in the IR spectrum is consistent with conversion of the reactant to the product?

A) absorption at 3200-3600 cm-1 should disappear

B) absorption at 3200-3600 cm-1 and 1100 cm-1 should disappear

C) absorption at 1100 cm-1 should disappear, a new absorption at 3100 cm-1 should appear

D) absorption at 1650 cm-1 should disappear, a new absorption at 3300 cm-1 should appear

E) none of these

Diff: 2

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

67) For the given reaction, which of the following change(s) in the IR spectrum is consistent with conversion of the reactant to the product?

A) absorption at 3300-3400 cm-1 should disappear

B) absorption at 3300-3400 cm-1 and 1100 cm-1 should disappear

C) absorption at 1100 cm-1 should disappear, a new absorption at 3100 cm-1 should appear

D) absorption at 1650 cm-1 should disappear, a new absorption at 3300 cm-1 should appear

E) absorption at 3300-3400 cm-1 should appear

Diff: 2

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

68) For the given reaction, explain how you can use IR spectroscopy to monitor the progress of the reaction.

Diff: 2

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

69) Predict the product for the reaction shown and explain how you can use IR spectroscopy to monitor the progress of the reaction.

A new absorption for OH at 3200-3600 cm-1 would appear in the product's IR spectrum.

Diff: 2

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

70) Predict the product for the reaction shown and explain how you can use IR spectroscopy to monitor the progress of the reaction.

A) CH3CH2CH2C≡CCH2CH2CH3; absorptions at around both 3300 cm-1 and 2150 cm-1 will disappear from the product spectrum

B) CH3C≡CCH2CH3; absorptions will remain the same but with smaller peaks

C) CH3CH2CH2C≡=CCH2CH2CH3; a single absorption at around 3300 cm-1 will disappear from the product spectrum

D) CH3CH2C≡CCH2CH2CH2CH3; a single absorption at around 2150 cm-1 will disappear from the product spectrum

E) CH3CH2CH2C≡=CCH2CH2CH3; absorptions will remain the same but become broader

Diff: 3

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

71) Predict the product for the reaction shown and explain how you can use IR spectroscopy to monitor the progress of the reaction.

A) The product will be I, there will be a new absorption at 3200-3600 cm-1, and an absorption at 1720 cm-1 will disappear.

B) The product will be I, there will be a new absorption at 1720 cm-1, and an absorption at 3200-3600 cm-1 will disappear.

C) The product will be II, there will be a new absorption at 3200-3600 cm-1, and an absorption at 1720 cm-1 will disappear.

D) The product will be III and an absorption at 1720 cm-1 will disappear.

E) The product will be III and an absorption at 3200-3600 cm-1 will disappear.

Diff: 3

Learning Objective: 14.7 Describe how IR spectroscopy can be used to distinguish between two compounds

72) Mass spectrometry is primarily used to determine ________.

A) molecular formula of a compound

B) molecular weight of a compound

C) conjugation in a compound

D) A and B

E) A and C

Diff: 1

Learning Objective: 14.8 Describe both the type of information that can be determined with mass spectrometry and how a mass spectrometer works

73) Which of the choices given is initially produced when a compound is bombarded with high energy electrons?

A) anions

B) free radicals

C) radical cations

D) cations

E) isotopes

Diff: 1

Learning Objective: 14.8 Describe both the type of information that can be determined with mass spectrometry and how a mass spectrometer works

74) Which of these statements is not true about the molecular ion in mass spectrometry?

A) The molecular ion is produced by loss of one electron from the molecule.

B) The mass of the molecular ion is equivalent to the mass of the molecule.

C) The ion is produced by a loss of pair of electrons from the molecule.

D) The molecular ion is often unstable and can undergo fragmentation.

Diff: 1

Learning Objective: 14.8 Describe both the type of information that can be determined with mass spectrometry and how a mass spectrometer works

75) Which of the statements given is always true about the base peak in a mass spectrum?

A) the peak corresponding to molecular ion

B) the peak corresponding to the most abundant ion

C) the peak corresponding to lowest m/z

D) the peak corresponding to the cation

E) the peak corresponding to the lowest fragment

Diff: 1

Learning Objective: 14.8 Describe both the type of information that can be determined with mass spectrometry and how a mass spectrometer works

76) The separation of ions in the mass spectrometer is done by their ________.

A) electrons to protons ratio

B) mass to neutrons ratio

C) protons to neutrons ratio

D) mass to charge ratio

E) protons to electrons ratio

Diff: 1

Learning Objective: 14.8 Describe both the type of information that can be determined with mass spectrometry and how a mass spectrometer works

77) In mass spectrometry using the electron impact ionization technique, a beam of high-energy electrons initially ejects one electron from the compound being studied. This produces a positively charged ion called the ________.

A) proton

B) molecular ion

C) central fragment

D) base peak

E) central peak

Diff: 1

Learning Objective: 14.8 Describe both the type of information that can be determined with mass spectrometry and how a mass spectrometer works

78) In mass spectrometry, the tallest peak is assigned an intensity of 100% and is referred to as the ________.

A) molecular peak

B) primary peak

C) central fragment

D) base peak

E) central peak

Diff: 1

Learning Objective: 14.8 Describe both the type of information that can be determined with mass spectrometry and how a mass spectrometer works

79) Which of the statements given is true about CH3CH3+•?

A) it is the parent ion of ethane

B) it is a molecular ion of ethane with m/z = 30

C) it is a fragment of propane

D) it is a fragment of butane

E) A and B

Diff: 1

Learning Objective: 14.9 Explain what is indicated by the M⁺• peak and what is indicated by an odd or even molecular weight

80) Which of the m/z values corresponds to the base peak in the mass spectrum shown?

A) 45

B) 44

C) 29

D) 15

E) 30

Diff: 1

Learning Objective: 14.9 Explain what is indicated by the M⁺• peak and what is indicated by an odd or even molecular weight

81) Which of the m/z values correspond to the molecular ion peak in the mass spectrum shown?

A) 45

B) 44

C) 29

D) 15

E) 30

Diff: 1

Learning Objective: 14.9 Explain what is indicated by the M⁺• peak and what is indicated by an odd or even molecular weight

82) Which of the m/z values correspond to the molecular ion for the compound shown?

A) 18

B) 82

C) 100

D) 102

E) 103

Diff: 2

Learning Objective: 14.9 Explain what is indicated by the M⁺• peak and what is indicated by an odd or even molecular weight

83) Which of the m/z values shown corresponds to the base peak for 2-chloro-2-methylpropane?

A) 15

B) 92

C) 77

D) 47

E) 57

Diff: 2

Learning Objective: 14.9 Explain what is indicated by the M⁺• peak and what is indicated by an odd or even molecular weight

84) Which of the compounds shown has an odd m/z value for the molecular ion?

A) I

B) II

C) III

D) IV

E) all of them

Diff: 2

Learning Objective: 14.9 Explain what is indicated by the M⁺• peak and what is indicated by an odd or even molecular weight

85) Which of the statements given is true about the molecular weight and the M+•-m/z value for the compound shown?

A) odd molecular weight, m/z = 115

B) odd molecular weight, m/z = 121

C) even molecular weight, m/z = 96

D) even molecular weight, m/z = 132

E) even molecular weight, m/z = 116

Diff: 2

Learning Objective: 14.10 Describe how the number of carbon atoms in a compound is determined using the (M+1)⁺• peak

86) Which of the statements given is true about the (M+1)+• peak on the mass spectrum of a hydrocarbon?

A) it is always the most abundant peak

B) it is due to the 13C isotope of carbon

C) it has a m/z value lower than the molecular ion

D) it is useful in calculating number of carbon atoms

E) B and D

Diff: 2

Learning Objective: 14.10 Describe how the number of carbon atoms in a compound is determined using the (M+1)⁺• peak

87) Which molecular formula is consistent with the given mass spectral data?

M+• at m/z = 84, relative height = 10.0%

(M+1)+• at m/ z = 85, relative height = 0.56%

A) C5H10O

B) C5H8O

C) C5H24

D) C6H12

E) C4H6O2

Diff: 2

Learning Objective: 14.10 Describe how the number of carbon atoms in a compound is determined using the (M+1)⁺• peak

88) Which molecular formula is consistent with the given mass spectral data?

M+• at m/z = 72, relative height = 73.0%

(M+1)+• at m/z = 73, relative height = 3.3%

A) C4H10O

B) C4H9N

C) C5H12

D) C4H8O

E) none of these

Diff: 2

Learning Objective: 14.10 Describe how the number of carbon atoms in a compound is determined using the (M+1)⁺• peak

89) Provide a molecular formula that is consistent with the given mass spectral data.

M+• at m/z = 73, relative height = 86.1%

(M+1)+• at m/z = 74, relative height = 3.2%

A) C2H14

B) C3H7NO

C) C3H8NO

D) C3H8O

E) C3H9NO

Diff: 2

Learning Objective: 14.10 Describe how the number of carbon atoms in a compound is determined using the (M+1)⁺• peak

90) Provide a molecular formula that is consistent with the given mass spectral data.

M+• at m/z = 136, relative height = 65.6%

(M+1)+ • at m/z = 137, relative height = 6.2%

A) C9H20O

B) C9H12O

C) C8H16O

D) C8H12O

E) C9H14O

Diff: 3

Learning Objective: 14.10 Describe how the number of carbon atoms in a compound is determined using the (M+1)⁺• peak

91) Provide a molecular formula that is consistent with the given mass spectral data.

M+• at m/z = 167, relative height = 50.0%

(M+1)+ • at m/z = 168, relative height = 4.4%

A) C8H9NH2

B) C9H18NO3

C) C9H9Br

D) C8H9NO3

E) C8H18NO3

Diff: 3

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

92) Compounds containing chlorine or bromine usually show a strong ________ peak.

A) molecular ion

B) base

C) M+1

D) M+2

E) all of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

93) Which of the chemicals shown produces M+• and (M+2)+• peaks of equal intensity?

A) nitrogen

B) chlorine

C) bromine

D) oxygen

E) B and C

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

94) Which of the chemicals shown produce an (M+2)+ • peak one third the intensity of the M+• peak?

A) nitrogen

B) chlorine

C) bromine

D) oxygen

E) B and C

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

95) Why does bromine produce M+• and (M+2)+• peaks of equal intensity on a mass spectrum?

A) The 81Br isotope has higher natural abundance than 79Br isotope.

B) The 79Br and 81Br isotopes have almost equal natural abundance.

C) The 79Br isotope has higher natural abundance than 81Br isotope.

D) none of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

96) Which molecular formula is consistent with the given mass spectral data?

M+• at m/z = 78, relative height = 23.5%

(M+1)+• at m/z = 79, relative height = 0.78%

(M+2)+• at m/z = 80, relative height = 7.5%

A) C6H6

B) C3H7Cl

C) C6H8

D) C6H9Cl

E) none of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

97) Which molecular formula is consistent with the given mass spectral data?

M+• at m/z = 108, relative height = 61.5%

(M+1)+• at m/z = 109, relative height = 1.5%

(M+2)+• at m/z = 110, relative height = 61.3%

A) C2H5Br

B) C5H12Cl

C) C8H12

D) C2H7Br

E) none of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

98) For which of the given compounds will the (M+2)+• peak intensity be around one third the intensity of the molecular ion peak?

A) CH3CH2CH2Br

B) CH3CH2CH2OH

C) CH3CH2CH2Cl

D) CH3CH2CH2NH2

E) none of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

99) For which of the given compounds will the (M+2)+• peak intensity be equal to the intensity of the molecular ion peak?

A) CH3CH2CH2Br

B) CH3CH2CH2OH

C) CH3CH2CH2Cl

D) CH3CH2CH2NH2

E) none of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

100) Which of the four mass spectra shown is consistent with the presence of bromine in a compound?

I

II

III

IV

Four spectra above: courtesy of SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) none of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

101) Which of the four mass spectra is consistent with the presence of chlorine in a compound?

I

II

III

IV

Four spectra above: courtesy of SDBS: National Institute of Advanced Industrial Science and Technology

A) I

B) II

C) III

D) IV

E) none of these

Diff: 2

Learning Objective: 14.11 Describe how the height of the (M+2)⁺• peak is affected by the presence of bromine or chlorine atoms

102) Which of the given compounds produces a prominent (M-18) peak in the mass spectrum?

A) 2-methylheptane

B) 1-heptanol

C) heptanamine

D) heptanal

E) none of these

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

103) Which of the given compounds produces a prominent (M-15) peak in the mass spectrum?

A) 2-methylheptane

B) 1-heptanol

C) heptanamine

D) 1-chloroheptane

E) none of these

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

104) Which of the choices is not a prominent peak in the mass spectrum of 2-methyl-2-pentanol?

A) (M-15)

B) (M-18)

C) (M-29)

D) (M-16)

E) none of these

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

105) Which of the given compounds has a prominent peak at (M-127)?

A) CH3CH2CH2I

B) (CH3CH2)3CCH2Cl

C) (CH3)3CCH2CH2Br

D) (CH3)2CHCH(CH3)2

E) none of these

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

106) Which of the given compounds has a base peak at m/z = 43?

A) CH3CH2CH2CH2CH2CH3

B) (CH3CH2)2CHCH3

C) (CH3)3CCH2CH3

D) (CH3)2CHCH(CH3)2

E) none of these

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

107) Which of the choices given is the base peak in the mass spectrum of 2,2,4-trimethylpentane?

A) 114

B) 57

C) 42

D) 29

E) none of these

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

108) Which of the choices given is expected to be the base peak in the mass spectrum of 2-methyl-2-butanol?

A) 73

B) 55

C) 43

D) 31

E) 59

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

109) Which of the choices given is expected to be the base peak in the mass spectrum of CH3CH2NH2?

A) 15

B) 28

C) 30

D) 45

E) none of these

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

110) Provide the structures of the fragments that result when the molecular ion of 2-heptanone undergoes fragmentation via McLafferty rearrangement.

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

111) Provide the structure of the major fragment that results when the molecular ion of (CH3)2CHCH2CH2NH2 undergoes fragmentation.

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

112) Provide the structure of the major fragment that results when the molecular ion of CH3CH2CH2CH2OH undergoes fragmentation via alpha cleavage.

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

113) Which of the choices given is expected to be the base peak in the mass spectrum of pentanal?

A) 29

B) 41

C) 44

D) 58

E) 86

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

114) Which one of the given compounds is consistent with the mass spectrum below?

SDBS: National Institute of Advanced Industrial Science and Technology

A) CH3CH2CH(CH3)2

B) CH3CHOHCH2CH3

C) CH3CH2OCH2CH3

D) CH3CH2NHCH2CH3

E) CH3CH2CH2CH3

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

115) Which one of the given compounds is consistent with the mass spectrum below?

SDBS: National Institute of Advanced Industrial Science and Technology

A) CH3CH2CH(CH3)2

B) CH3CHOHCH2CH3

C) CH3CH2OCH2CH3

D) CH3CH2NHCH2CH3

E) CH3CH2CH2CH3

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

116) Which one of the given compounds is consistent with the mass spectrum below?

SDBS: National Institute of Advanced Industrial Science and Technology

A) CH3CH2CH(CH3)2

B) CH3CHOHCH2CH3

C) CH3CH2OCH2CH3

D) CH3CH2NHCH2CH3

E) CH3CH2CH2CH3

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

117) Which one of the given compounds is consistent with the mass spectrum below?

SDBS: National Institute of Advanced Industrial Science and Technology

A) (CH3CH2CH2)2CH

B) CH3CH2CHOHCH2CH2CH3

C) (CH3CH2CH2)2O

D) (CH3CH2CH2)2NH

E) CH3CH2CH2CH3

Diff: 2

Learning Objective: 14.12 Describe the characteristic fragmentation patterns of alkanes, alcohols, amines, aldehydes, and ketones

118) High-resolution mass spectrometry is used to determine the ________ of a compound.

A) degree of unsaturation

B) molecular formula

C) molecular weight

D) B and C

E) none of these

Diff: 1

Learning Objective: 14.13 Identify the characteristic of an organic compound that can be determined with high resolution mass spectrometry

119) How can you distinguish between the given compounds using high-resolution mass spectrometry?

A) Compound I: m/z at 103.0678; Compound II: m/z at 103.0235

B) Compound I: m/z at 102.0678; Compound II: m/z at 102.0235

C) Compound I: m/z at 102.0235; Compound I: m/z at 102.0678

D) Compound I: m/z at 103.0235; Compound II: m/z at 102.0678

E) Compound I: m/z at 102.0678; Compound II: m/z at 103.0235

Diff: 2

Learning Objective: 14.13 Identify the characteristic of an organic compound that can be determined with high resolution mass spectrometry

120) How can you distinguish between the given compounds using high-resolution mass spectrometry?

A) Compound I: m/z at 98; Compound II: m/z at 99

B) Compound I: m/z at 99.1092; Compound II: m/z at 99.0729

C) Compound I: m/z at 99.0729; Compound II: m/z at 99.1092

D) Compound I: m/z at 98.1092; Compound II: m/z at 98.0729

E) Compound I: m/z at 98.0729; Compound II: m/z at 98.1092

Diff: 2

Learning Objective: 14.13 Identify the characteristic of an organic compound that can be determined with high resolution mass spectrometry

121) GC-mass spectrometry is used to find the ________ of each compound in a ________.

A) molecular formula, mixture of alkanes

B) molecular weight, mixture of compounds

C) molecular formula, mixture of compounds

D) B and C

E) none of these

Diff: 2

Learning Objective: 14.14 Describe the functions of a gas chromatograph—mass spectrometer (GC-MS)

122) A stationary phase separates the components of a mixture based on their ________ and ________.

A) boiling points, their affinity for the stationary phase

B) melting points, their repulsion for the stationary phase

C) molecular weights, melting points

D) solubility in water, in methanol

E) heat of vaporization, heat of sublimation

Diff: 1

Learning Objective: 14.14 Describe the functions of a gas chromatograph—mass spectrometer (GC-MS)

123) Define retention time.

A) the amount of time that the substance takes to boil

B) the amount of time that the substance takes to melt

C) the amount of time required to exit from the mass spectrometer

D) the amount of time required to exit from the gas chromatograph

E) the amount of time required to set up the GC-MS

Diff: 1

Learning Objective: 14.14 Describe the functions of a gas chromatograph—mass spectrometer (GC-MS)

124) Electrospray ionization is used to obtain mass spectra of proteins because ________.

A) it allows for faster fragmentation of the molecular ion

B) the molecular ion usually does not undergo fragmentation

C) it allows for slow fragmentation of the molecular ion

D) the proteins are liquids

Diff: 2

Learning Objective: 14.15 Explain how large biomolecules are ionized for analysis by mass spectrometry

125) Identify the medical application that does not use mass spectrometry.

A) cancer detection

B) metabolic defects in babies

C) pathogenic bacteria

D) drug analysis

E) all of these applications use mass spectrometry

Diff: 1

Learning Objective: 14.15 Explain how large biomolecules are ionized for analysis by mass spectrometry

126) Calculate the degree of unsaturation for C9H11N.

A) 4

B) 6

C) 2

D) 5

E) 3

Diff: 1

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

127) Calculate the degree of unsaturation for C14H14N2O.

A) 4

B) 6

C) 8

D) 10

E) 9

Diff: 1

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

128) Calculate the degree of unsaturation for C11H8ClBrO.

A) 4

B) 6

C) 7

D) 8

E) 10

Diff: 1

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

129) Calculate the degree of unsaturation for C5H5Br2NO.

A) 4

B) 6

C) 2

D) 3

E) 7

Diff: 2

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

130) Which of the compounds shown have the same degree of unsaturation?

A) I and II

B) I and III

C) III and IV

D) II and III

E) none of these

Diff: 2

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

131) Propose a possible structure for a compound with molecular formula C6H5Br.

A) I

B) II

C) III

D) IV

E) V

Diff: 2

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

132) Propose all possible structures for a compound with molecular formula C4H9N that shows two medium absorptions at 3400 cm-1 and no absorption in the range of 1600 — 1800 cm-1 in its IR spectrum.

A) I

B) II

C) III

D) I and II

E) I, II, III, and IV

Diff: 2

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

133) Propose possible structure(s) for a compound with molecular formula C4H7N that shows absorption at 2250 cm-1 in its IR spectrum.

A) CH3CH2CH2C≡N

B) CH3NHC≡CCH3

C) (CH3)2CHC≡N

D) A and B

E) A and C

Diff: 2

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

134) Propose a possible structure for a compound with molecular formula C7H12O2 that shows absorption at 1720 cm-1 and no absorption in the range of 1500 — 1700 cm-1 or 2600 — 2800 cm-1 in its IR spectrum.

A) I

B) II

C) III

D) I and II

E) II and III

Diff: 2

Learning Objective: 14.16 Discuss the degree of unsaturation of a compound and explain the HDI and how it is useful

135) Based on the given IR spectrum and mass spectrum of an unknown compound, what is a possible structure for the unknown compound?

SDBS

A) (CH3CH2CH2)3C

B) (CH3CH2)2NH

C) (CH3CH2CH2)2NH

D) CH3C(O)CH2NH

E) CH3CH2CH2CH2CH2CH2NH

Diff: 2

Learning Objective: 14.6 Define the process for analyzing an IR spectrum

© (2021) John Wiley & Sons, Inc. All rights reserved. Instructors who are authorized users of this course are permitted to download these materials and use them in connection with the course. Except as permitted herein or by law, no part of these materials should be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise.