Question 1

Which of the following structures is consistent with a compound that displays a molecular ion peak at 103 and infrared signals at 2250 and 1600 cm-1?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV A

Question 2

A compound X shows a molecular ion peak at m/z 72 in its mass spectrum,and a strong peak at ~1715 cm-1 in its IR spectrum.Which structures are possible for compound X?

Accepted Answer

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

Question 3

Which of the following statements is (are)true about a compound that has a molecular ion peak in its mass spectrum at mass 94 and shows prominent peaks in its IR spectrum at 3600-3200 and 1600 cm-1?

Accepted Answer

A) The compound has a molecular mass of 94. 
B) The compound contains a C=O group and Csp3-H hybridized bonds. 
C) The compound contains an OH group and a benzene ring. 
D) Both (The compound has a molecular mass of 94)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 94)and (The compound contains an OH group and a benzene ring)are true statements. 
A) The compound has a molecular mass of 94. 
B) The compound contains a C=O group and Csp3-H hybridized bonds. 
C) The compound contains an OH group and a benzene ring. 
D) Both (The compound has a molecular mass of 94)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 94)and (The compound contains an OH group and a benzene ring)are true statements. E

Question 4

Examine the IR below and classify the compound.

Accepted Answer

A) Alcohol 
B) Aldehyde 
C) Amine 
D) Ketone 
E) Carboxylic acid 
A) Alcohol 
B) Aldehyde 
C) Amine 
D) Ketone 
E) Carboxylic acid

Question 5

Examine the IR below and classify the compound.

Accepted Answer

A) Alkane 
B) Carboxylic acid 
C) Alcohol 
D) Alkene 
A) Alkane 
B) Carboxylic acid 
C) Alcohol 
D) Alkene

Question 6

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

Accepted Answer

A) 3300 cm-1 
B) 3100 cm-1 
C) 2250 cm-1 
D) 1750 cm-1 
A) 3300 cm-1 
B) 3100 cm-1 
C) 2250 cm-1 
D) 1750 cm-1

Question 7

When the phenol shown below is treated with KOH,it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm-1 region.Propose a structure for the product.

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 8

Examine the IR below and classify the compound.

Accepted Answer

A) Alcohol 
B) Aldehyde 
C) Amine 
D) Ketone 
A) Alcohol 
B) Aldehyde 
C) Amine 
D) Ketone

Question 9

Which of the following statement(s)is (are)true about a compound that has a molecular ion peak in its mass spectrum at mass 69 and shows a prominent peak in its IR spectrum at 2250 cm-1?

Accepted Answer

A) The compound has a molecular mass of 70. 
B) The compound contains a C=O group. 
C) The compound contains a cyano or alkyne group. 
D) Both (The compound has a molecular mass of 70)and (The compound contains a C=O group)are true statements. 
E) Both (The compound has a molecular mass of 70)and (The compound contains a cyano or alkyne group)are true statements. 
A) The compound has a molecular mass of 70. 
B) The compound contains a C=O group. 
C) The compound contains a cyano or alkyne group. 
D) Both (The compound has a molecular mass of 70)and (The compound contains a C=O group)are true statements. 
E) Both (The compound has a molecular mass of 70)and (The compound contains a cyano or alkyne group)are true statements.

Question 10

Why does an alkyne carbon-carbon triple bond vibrate at a higher wavenumber than an alkene carbon-carbon double bond?

Accepted Answer

A) It is stronger. 
B) It is weaker. 
C) It has fewer hydrogens. 
D) It makes a less stable cation. 
A) It is stronger. 
B) It is weaker. 
C) It has fewer hydrogens. 
D) It makes a less stable cation.

Question 11

The base peak in a mass spectrum corresponds to the most stable fragment.Propose a structure for a compound that is consistent with the following data. 
a.The molecular ion peak has m/z = 116.
b.The base peak is at m/z = 59.
c.The compound is composed of C,H and O atoms.
d.The IR spectrum shows a strong absorbance at 3257 cm-1.

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 12

Which of the following structures is consistent with a compound that displays a molecular ion peak at 84 and infrared signals at 3000-2850 cm-1 and no signals between 3000-3300 cm-1?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 13

Stronger bonds will be found where in the infrared spectrum?

Accepted Answer

A) Higher molecular weight 
B) Lower molecular weight 
C) Lower wavenumbers 
D) Higher wavenumbers 
A) Higher molecular weight 
B) Lower molecular weight 
C) Lower wavenumbers 
D) Higher wavenumbers

Question 14

An alkyne C-H bond absorbs at higher wave number than an alkene C-H bond.What does this tell you about the strength of these two bonds?

Accepted Answer

A) The alkene C-H bond is stronger. 
B) The alkyne C-H bond is stronger. 
C) The alkene C-C bond is stronger. 
D) The alkyne C-C bond is stronger. 
A) The alkene C-H bond is stronger. 
B) The alkyne C-H bond is stronger. 
C) The alkene C-C bond is stronger. 
D) The alkyne C-C bond is stronger.

Question 15

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

Accepted Answer

A) A signal at 1600 cm-1 
B) A signal at 3300 cm-1 
C) A single mass peak at 92 amu 
D) Two mass peaks at 92 and 94 amu 
A) A signal at 1600 cm-1 
B) A signal at 3300 cm-1 
C) A single mass peak at 92 amu 
D) Two mass peaks at 92 and 94 amu

Question 16

The functional group region of an infrared spectrum is

Accepted Answer

A) where the cations appear. 
B) greater than or equal to 1500 cm-1. 
C) less than 1500 cm-1. 
D) greater than or equal to 2500 cm-1. 
A) where the cations appear. 
B) greater than or equal to 1500 cm-1. 
C) less than 1500 cm-1. 
D) greater than or equal to 2500 cm-1.

Question 17

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

Accepted Answer

A) A signal at 95 amu 
B) A signal at 94 amu 
C) Two signals at 95 and 94 amu 
D) A signal at 3600-3200 cm-1 
A) A signal at 95 amu 
B) A signal at 94 amu 
C) Two signals at 95 and 94 amu 
D) A signal at 3600-3200 cm-1

Question 18

Which of the following π bonds is IR inactive?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 19

In an IR spectrum,which of the indicated C-H bonds exhibits a stretching absorption at the largest wave number?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
A) I 
B) II 
C) III 
D) IV

Question 20

-Which of the following statements is (are)true about the IR spectrum of the compound drawn below?

Accepted Answer

A) It shows absorptions at 3000-3150 cm-1 and 1720 cm-1. 
B) It shows absorptions at 3000-2850 cm-1 and 2150 cm-1. 
C) It shows absorptions at 2250 cm-1 and 1650 cm-1. 
D) It shows absorptions at 2250 cm-1 and 1720 cm-1. 
E) Both statements (It shows absorptions at 3000-2850 cm-1 and 2250 cm-1)and (It shows absorptions at 2250 cm-1 and 1720 cm-1)are true. 
A) It shows absorptions at 3000-3150 cm-1 and 1720 cm-1. 
B) It shows absorptions at 3000-2850 cm-1 and 2150 cm-1. 
C) It shows absorptions at 2250 cm-1 and 1650 cm-1. 
D) It shows absorptions at 2250 cm-1 and 1720 cm-1. 
E) Both statements (It shows absorptions at 3000-2850 cm-1 and 2250 cm-1)and (It shows absorptions at 2250 cm-1 and 1720 cm-1)are true.

Exam 31: Spectroscopy B: Infrared Spectroscopy

Which of the following structures is consistent with a compound that displays a molecular ion peak at 103 and infrared signals at 2250 and 1600 cm-1?

A compound X shows a molecular ion peak at m/z 72 in its mass spectrum,and a strong peak at ~1715 cm-1 in its IR spectrum.Which structures are possible for compound X?

Which of the following statements is (are)true about a compound that has a molecular ion peak in its mass spectrum at mass 94 and shows prominent peaks in its IR spectrum at 3600-3200 and 1600 cm-1?

Examine the IR below and classify the compound.

Examine the IR below and classify the compound.

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

When the phenol shown below is treated with KOH,it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm-1 region.Propose a structure for the product.

Examine the IR below and classify the compound.

Which of the following statement(s)is (are)true about a compound that has a molecular ion peak in its mass spectrum at mass 69 and shows a prominent peak in its IR spectrum at 2250 cm-1?

Why does an alkyne carbon-carbon triple bond vibrate at a higher wavenumber than an alkene carbon-carbon double bond?

Which of the following structures is consistent with a compound that displays a molecular ion peak at 84 and infrared signals at 3000-2850 cm-1 and no signals between 3000-3300 cm-1?

Stronger bonds will be found where in the infrared spectrum?

An alkyne C-H bond absorbs at higher wave number than an alkene C-H bond.What does this tell you about the strength of these two bonds?

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

The functional group region of an infrared spectrum is

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

Which of the following π bonds is IR inactive?

In an IR spectrum,which of the indicated C-H bonds exhibits a stretching absorption at the largest wave number?

-Which of the following statements is (are)true about the IR spectrum of the compound drawn below?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols,ethers,and Related Compounds

Alkenes and Addition Reactions

Alkynes and Synthesis

Oxidation and Reduction

Radical Reactions

Conjugation,resonance,and Dienes

Benzene and Aromatic Compounds

Reactions of Aromatic Compounds

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones - Nucleophilic Addition

Carboxylic Acids and the Acidity of the O-H Bond

Carboxylic Acids and Their Derivatives Nucleophilic Acyl Substitution

Substitution Reactions of Carbonyl Compounds at the a Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond-Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

Amino Acids and Proteins

Synthetic Polymers

Lipids

Spectroscopy A: Mass Spectrometry

Spectroscopy C: Nuclear Magnetic Resonance Spectroscopy

Filters

Which of the following structures is consistent with a compound that displays a molecular ion peak at 103 and infrared signals at 2250 and 1600 cm^-1?

A compound X shows a molecular ion peak at m/z 72 in its mass spectrum,and a strong peak at ~1715 cm^-1 in its IR spectrum.Which structures are possible for compound X?

Which of the following statements is (are)true about a compound that has a molecular ion peak in its mass spectrum at mass 94 and shows prominent peaks in its IR spectrum at 3600-3200 and 1600 cm^-1?

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

When the phenol shown below is treated with KOH,it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm^-1 region.Propose a structure for the product.

Which of the following statement(s)is (are)true about a compound that has a molecular ion peak in its mass spectrum at mass 69 and shows a prominent peak in its IR spectrum at 2250 cm^-1?

Which of the following structures is consistent with a compound that displays a molecular ion peak at 84 and infrared signals at 3000-2850 cm^-1 and no signals between 3000-3300 cm^-1?