Question 1

Why is the infrared absorption for the stretching motion of internal alkynes rarely observed?

Accepted Answer

A)  They do not form cations.
B)  They are too strong.
C)  Stretching in internal alkynes does not involve a change in dipole moment.
D)  They do not have hydrogens.E) All of the above
F) A) and B)

Question 2

Which of the indicated C-H bonds absorbs at the lowest wave number in the IR spectrum?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) A) and B)
F) A) and C)

Question 3

Which of the following structures is consistent with a compound that displays a molecular ion peak at 56 and infrared signals at 2250 and 3600-3200 cm-1? -1?   A) I B) II C) III D) IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) A) and B)
F) B) and D)

Question 4

Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 104 and shows prominent peaks in its IR spectrum at 3200-2850 cm-1?

Accepted Answer

A)  The compound has a molecular mass of 104.
B)  The compound contains a C=O group and Csp3-H hybridized bonds.
C)  The compound contains an OH group and Csp3-H hybridized bonds.
D)  Both (The compound has a molecular mass of 104) and (The compound contains a C=O group and Csp3-H hybridized bonds) are true statements.
E)  Both (The compound has a molecular mass of 104) and (The compound contains an OH group and Csp3-H hybridized bonds) are true statements.F) A) and E)
G) B) and E)

Question 5

You are given a bottle of an organic liquid and told it must be either cyclohexane or 1-hexene.Which of the following statements is (are) true about these two compounds? -1 but cyclohexane will not. C) Both cyclohexane and 1-hexene will show C-H absorptions at about 2950 cm-1. D) Statements (1-Hexene will show an absorption at 1650 cm-1 but cyclohexane will not) and (Both cyclohexane and 1-hexene will show C-H absorptions at about 2950 cm-1) are both true. E) Statements (The two compounds can be differentiated by their mass spectra because they will have molecular ions at different masses) ,(1-Hexene will show an absorption at 1650 cm-1 but cyclohexane will not) ,and (Both cyclohexane and 1- hexene will show C-H absorptions at about 2950 cm-1) are all true." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  The two compounds can be differentiated by their mass spectra because they will have molecular ion peaks at different m/z.
B)  1-Hexene will show an absorption at 1650 cm-1 but cyclohexane will not.
C)  Both cyclohexane and 1-hexene will show C-H absorptions at about 2950 cm-1.
D)  Statements (1-Hexene will show an absorption at 1650 cm-1 but cyclohexane will not) and (Both cyclohexane and 1-hexene will show C-H absorptions at about 2950 cm-1) are both true.
E)  Statements (The two compounds can be differentiated by their mass spectra because they will have molecular ions at different masses) ,(1-Hexene will show an absorption at 1650 cm-1 but cyclohexane will not) ,and (Both cyclohexane and 1- hexene will show C-H absorptions at about 2950 cm-1) are all true.F) All of the above
G) D) and E)

Question 6

Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) All of the above
F) B) and C)

Question 7

What type of signal(s) would you observe in the mass and/or infrared spectrum of the following compound? -1 D) A signal at 1720 cm-1" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  A signal at 96 amu
B)  Two signals at 112 and 114 amu
C)  A signal at 1600 cm-1
D)  A signal at 1720 cm-1E) B) and C)
F) A) and D)

Question 8

Which of the following statements is (are) accurate about the IR spectrum of compounds I,II,and III below? -1. B) Compound II shows absorptions at 3200-3600 and 1650 cm-1. C) Compound III shows absorptions at 3200-3600 and 2950 cm-1. D) Both (Compound I shows absorptions at 2950 and 1700 cm-1) and (Compound II shows absorptions at 3200-3600 and 1650 cm-1) are true." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  Compound I shows absorptions at 2950 and 1700 cm-1.
B)  Compound II shows absorptions at 3200-3600 and 1650 cm-1.
C)  Compound III shows absorptions at 3200-3600 and 2950 cm-1.
D)  Both (Compound I shows absorptions at 2950 and 1700 cm-1) and (Compound II shows absorptions at 3200-3600 and 1650 cm-1) are true.E) A) and B)
F) A) and C)

Question 9

Which of the following statements is (are) true about a compound that has molecular ion peaks in its mass spectrum at mass 170 and 172 and shows prominent peaks in its IR spectrum at 3150-3000 and 1600 cm-1?

Accepted Answer

A)  The compound is not pure.
B)  The compound contains a halogen.
C)  The compound contains an OH group and Csp3-H hybridized bonds.
D)  Both (The compound is not pure) and (The compound contains a halogen) are true statements.
E)  Both (The compound is not pure) and (The compound contains an OH group and Csp3-H hybridized bonds) are true statements.F) A) and B)
G) C) and D)

Question 10

Compared to a C-H bond,a C-D bond will vibrate where in the infrared spectrum?

Accepted Answer

A)  Higher molecular weight
B)  Lower molecular weight
C)  Lower wavenumbers
D)  Higher wavenumbersE) None of the above
F) C) and D)

Question 11

Examine the IR below and classify the compound.

Accepted Answer

A)  Alcohol
B)  Arene
C)  Amine
D)  Ketone
E)  Carbocylic acidF) B) and D)
G) A) and B)

Question 12

Which of the following information is primarily obtained from an IR spectrum?

Accepted Answer

A)  Conjugated p system present in a compound.
B)  Functional groups present in a compound.
C)  Molecular weight of a compound.
D)  The carbon and hydrogen framework of a compound.E) A) and B)
F) B) and C)

Question 13

13C NMR is a technique in which the total number of signals represents the number of unique carbon atoms in a molecule.Propose a structure that is consistent with the following data. a.The IR includes peaks at 1603 and 1495 cm-1.
b.The 13C NMR has a total of 7 signals.
c.The compound has one acidic proton. 13C NMR is a technique in which the total number of signals represents the number of unique carbon atoms in a molecule.Propose a structure that is consistent with the following data. a.The IR includes peaks at 1603 and 1495 cm-1. b.The 13C NMR has a total of 7 signals. c.The compound has one acidic proton.   A) I B) II C) III D) IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) A) and D)
F) B) and D)

Question 14

What type(s) of molecular motion is (are) observed using infrared spectroscopy?

Accepted Answer

A)  Stretching and bending
B)  Rotation and excitation
C)  Spin flipping
D)  FragmentationE) A) and B)
F) A) and C)

Question 15

Consider the three organic compounds drawn below.Which of the following statements is (are) true about the IR spectra of I,II,and III? -1 and 1700 cm-1. B) II shows strong absorptions at 2950 cm-1 and 2250 cm-1. C) III shows strong absorptions at 2950 cm-1 and 3200-3600 cm-1. D) Statements (I shows strong absorptions at 2950 cm-1 and 1700 cm-1) and (III shows strong absorptions at 2950 cm-1 and 3200-3600 cm-1) are true." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  I shows strong absorptions at 2950 cm-1 and 1700 cm-1.
B)  II shows strong absorptions at 2950 cm-1 and 2250 cm-1.
C)  III shows strong absorptions at 2950 cm-1 and 3200-3600 cm-1.
D)  Statements (I shows strong absorptions at 2950 cm-1 and 1700 cm-1) and (III shows strong absorptions at 2950 cm-1 and 3200-3600 cm-1) are true.E) C) and D)
F) A) and B)

Question 16

An IR spectrum has the following potentially important absorptions: 3091,3067,2963,2921,2252,1603,1499,1455,1416,1078,1031,941,735,and 696 cm-1.Indicate which structure corresponds to the IR data. -1.Indicate which structure corresponds to the IR data.   A) I B) II C) III D) IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) None of the above
F) A) and B)

Question 17

Ignoring sp3 CH stretching,estimate where the major peak be in the following compound's IR. 3 CH stretching,estimate where the major peak be in the following compound's IR.   A) 3300 cm-1 B) 3100 cm-1 C) 2250 cm-1 D) 1750 cm-1" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  3300 cm-1
B)  3100 cm-1
C)  2250 cm-1
D)  1750 cm-1E) C) and D)
F) None of the above

Question 18

Ignoring sp3 CH stretching,estimate where the major peak be in the following compound's IR. 3 CH stretching,estimate where the major peak be in the following compound's IR.   A) 3300 cm-1 B) 3100 cm-1 C) 2250 cm-1 D) 1750 cm-1" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  3300 cm-1
B)  3100 cm-1
C)  2250 cm-1
D)  1750 cm-1E) None of the above
F) B) and C)

Question 19

Examine the IR below and classify the compound.

Accepted Answer

A)  Alcohol
B)  Aldehyde
C)  Carboxylic acid
D)  KetoneE) A) and B)
F) A) and C)

Exam 31: Spectroscopy B: Infrared Spectroscopy

What type(s) of molecular motion is (are) observed using infrared spectroscopy?

Correct Answer
verified

Compared to a C-H bond,a C-D bond will vibrate where in the infrared spectrum?

Correct Answer
verified

Which of the following statements is (are) true about a compound that has molecular ion peaks in its mass spectrum at mass 170 and 172 and shows prominent peaks in its IR spectrum at 3150-3000 and 1600 cm^-1?

Correct Answer
verified

An IR spectrum has the following potentially important absorptions: 3091,3067,2963,2921,2252,1603,1499,1455,1416,1078,1031,941,735,and 696 cm^-1.Indicate which structure corresponds to the IR data.

Correct Answer
verified

Examine the IR below and classify the compound.

Correct Answer
verified

Which of the indicated C-H bonds absorbs at the lowest wave number in the IR spectrum?

Correct Answer
verified

Consider the three organic compounds drawn below.Which of the following statements is (are) true about the IR spectra of I,II,and III?

Correct Answer
verified

Correct Answer
verified

Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 104 and shows prominent peaks in its IR spectrum at 3200-2850 cm^-1?

Correct Answer
verified

Which of the following information is primarily obtained from an IR spectrum?

Correct Answer
verified

Examine the IR below and classify the compound.

Correct Answer
verified

Why is the infrared absorption for the stretching motion of internal alkynes rarely observed?

Correct Answer
verified

What type of signal(s) would you observe in the mass and/or infrared spectrum of the following compound?

Correct Answer
verified

Which of the following statements is (are) accurate about the IR spectrum of compounds I,II,and III below?

Correct Answer
verified

Which of the following structures is consistent with a compound that displays a molecular ion peak at 56 and infrared signals at 2250 and 3600-3200 cm^-1?

Correct Answer
verified

You are given a bottle of an organic liquid and told it must be either cyclohexane or 1-hexene.Which of the following statements is (are) true about these two compounds?

Correct Answer
verified

Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Correct Answer
verified

Ignoring sp³ CH stretching,estimate where the major peak be in the following compound's IR.

Correct Answer
verified

Ignoring sp³ CH stretching,estimate where the major peak be in the following compound's IR.

Correct Answer
verified

Exam 31: Spectroscopy B: Infrared Spectroscopy

What type(s) of molecular motion is (are) observed using infrared spectroscopy?

Correct AnswerverifiedShow Answer

Compared to a C-H bond,a C-D bond will vibrate where in the infrared spectrum?

Correct AnswerverifiedShow Answer

Which of the following statements is (are) true about a compound that has molecular ion peaks in its mass spectrum at mass 170 and 172 and shows prominent peaks in its IR spectrum at 3150-3000 and 1600 cm-1?

Correct AnswerverifiedShow Answer

An IR spectrum has the following potentially important absorptions: 3091,3067,2963,2921,2252,1603,1499,1455,1416,1078,1031,941,735,and 696 cm-1.Indicate which structure corresponds to the IR data.

Correct AnswerverifiedShow Answer

Examine the IR below and classify the compound.

Correct AnswerverifiedShow Answer

Which of the indicated C-H bonds absorbs at the lowest wave number in the IR spectrum?

Correct AnswerverifiedShow Answer

Consider the three organic compounds drawn below.Which of the following statements is (are) true about the IR spectra of I,II,and III?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 104 and shows prominent peaks in its IR spectrum at 3200-2850 cm-1?

Correct AnswerverifiedShow Answer

Which of the following information is primarily obtained from an IR spectrum?

Correct AnswerverifiedShow Answer

Examine the IR below and classify the compound.

Correct AnswerverifiedShow Answer

Why is the infrared absorption for the stretching motion of internal alkynes rarely observed?

Correct AnswerverifiedShow Answer

What type of signal(s) would you observe in the mass and/or infrared spectrum of the following compound?

Correct AnswerverifiedShow Answer

Which of the following statements is (are) accurate about the IR spectrum of compounds I,II,and III below?

Correct AnswerverifiedShow Answer

Which of the following structures is consistent with a compound that displays a molecular ion peak at 56 and infrared signals at 2250 and 3600-3200 cm-1?

Correct AnswerverifiedShow Answer

You are given a bottle of an organic liquid and told it must be either cyclohexane or 1-hexene.Which of the following statements is (are) true about these two compounds?

Correct AnswerverifiedShow Answer

Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Correct AnswerverifiedShow Answer

Ignoring sp3 CH stretching,estimate where the major peak be in the following compound's IR.

Correct AnswerverifiedShow Answer

Ignoring sp3 CH stretching,estimate where the major peak be in the following compound's IR.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Which of the following statements is (are) true about a compound that has molecular ion peaks in its mass spectrum at mass 170 and 172 and shows prominent peaks in its IR spectrum at 3150-3000 and 1600 cm^-1?

Correct Answer
verified

An IR spectrum has the following potentially important absorptions: 3091,3067,2963,2921,2252,1603,1499,1455,1416,1078,1031,941,735,and 696 cm^-1.Indicate which structure corresponds to the IR data.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 104 and shows prominent peaks in its IR spectrum at 3200-2850 cm^-1?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Which of the following structures is consistent with a compound that displays a molecular ion peak at 56 and infrared signals at 2250 and 3600-3200 cm^-1?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Ignoring sp³ CH stretching,estimate where the major peak be in the following compound's IR.

Correct Answer
verified

Ignoring sp³ CH stretching,estimate where the major peak be in the following compound's IR.

Correct Answer
verified