Question 1

Account for fragments having a m/z value of 45 and 55 in the mass spectrum of 2-hexanol by drawing structures of the fragments.

Accepted Answer

The answer of Account for fragments having a m/z value...

Question 2

What functional groups are represented in the following IR spectrum?

Accepted Answer

alcohol and aromatic

Question 3

The region of the IR spectrum which generally contains the complex bending vibrations   
is called the ________ region of the spectrum.

Accepted Answer

The answer of The region of the IR spectrum which...

Question 4

What effect does conjugation typically have on the frequency at which absorption by C   C occurs?

Accepted Answer

A)  Conjugation decreases the frequency at which absorption occurs. 
B)  Conjugation increases the frequency at which absorption occurs. 
C)  Conjugation does not affect the frequency at which absorption occurs. 
A)  Conjugation decreases the frequency at which absorption occurs. 
B)  Conjugation increases the frequency at which absorption occurs. 
C)  Conjugation does not affect the frequency at which absorption occurs.

Question 5

Which compound would show a larger than usual M+2 peak in the mass spectrum?

Accepted Answer

A)  CH3CH2SCH3 
B)  (CH3)2CHNH2 
C)  CH3CH2CO2H 
D)  CH3(CH2)2CH3 
A)  CH3CH2SCH3 
B)  (CH3)2CHNH2 
C)  CH3CH2CO2H 
D)  CH3(CH2)2CH3

Question 6

Which compound would be expected to show intense IR absorption at 3363, 3185, 1660 cm-1?

Accepted Answer

A)  CH3CH2CH2OH 
B)  (CH3)2CHNH2 
C)  CH3CH2CONH2 
D)  but-1-ene 
A)  CH3CH2CH2OH 
B)  (CH3)2CHNH2 
C)  CH3CH2CONH2 
D)  but-1-ene

Question 7

How could you tell if the hydrogenation of 2-pentene to pentane was complete?

Accepted Answer

The 1600 and 3050 cm

Question 8

Which of the following compounds has the lowest carbonyl stretching frequency?

Accepted Answer

The answer of Which of the following compounds has the...

Question 9

Which compound would be expected to show an IR absorption at 3300 cm-1?

Accepted Answer

A)  CH3C   CCH3 
B)  butane 
C)  but-1-ene 
D)  CH3CH2C   CH 
A)  CH3C   CCH3 
B)  butane 
C)  but-1-ene 
D)  CH3CH2C   CH

Question 10

Which of the following compounds would contain characteristic IR stretches at 3300 and 2200 cm-1?

Accepted Answer

A)  CH3CH2CHO 
B)  CH3CH=CHCH2OH 
C)  (CH3)2CHCN 
D)  CH3CH2CH2C≡CH 
E)  CH3C≡CCH2CH3 
A)  CH3CH2CHO 
B)  CH3CH=CHCH2OH 
C)  (CH3)2CHCN 
D)  CH3CH2CH2C≡CH 
E)  CH3C≡CCH2CH3

Question 11

Could pentane and heptane easily be distinguished by IR spectroscopy?

Accepted Answer

No. They would have

Question 12

Which has a lower characteristic stretching frequency, the C   
O bond or the C-O bond? Explain briefly.

Accepted Answer

Stronger bonds are generally s

Question 13

Absorption of what type of electromagnetic radiation results in transitions among allowed nuclear magnetic spin states?

Accepted Answer

A)  X-rays 
B)  radio waves 
C)  microwaves 
D)  ultraviolet light 
E)  infrared light 
A)  X-rays 
B)  radio waves 
C)  microwaves 
D)  ultraviolet light 
E)  infrared light

Question 14

Which region of the electromagnetic spectrum, radio or visible, is characterized by waves of shorter wavelength?

Accepted Answer

The answer of Which region of the electromagnetic spectrum, radio...

Question 15

Which compound would be expected to show intense IR absorption at 2250 cm-1?

Accepted Answer

A)  CH3CH2CH2CO2H 
B)  (CH3)2CHCH2OH 
C)  (CH3)2CHCN 
D)  CH3CH2CH2CONH2 
A)  CH3CH2CH2CO2H 
B)  (CH3)2CHCH2OH 
C)  (CH3)2CHCN 
D)  CH3CH2CH2CONH2

Question 16

In which unit is frequency measured?

Accepted Answer

A)  joule 
B)  Kcal 
C)  hertz 
D)  gauss 
A)  joule 
B)  Kcal 
C)  hertz 
D)  gauss

Question 17

How could IR spectroscopy be used to distinguish between the following pair of compounds?
CH3COCH   
CHCH2CH3 and CH3COCH2CH2CH   
CH2

Accepted Answer

C @#IMG-DLM& O absorption in c

Question 18

How could IR spectroscopy be used to distinguish between the following pair of compounds?
CH3OCH2CH3 and CH3CH2CH2OH

Accepted Answer

O-H stretc

Question 19

Deduce a possible structure for the compound with the IR absorptions below.
C5H8O: 2950, 1750 cm-1

Accepted Answer

Question 20

Which compound would be expected to show intense IR absorption at 1746 cm-1?

Accepted Answer

A)  CH3CH2OCH2CH3 
B)  CH3CH2CN 
C)  CH3CO2CH2CH3 
D)  CH3CH2SCH3 
A)  CH3CH2OCH2CH3 
B)  CH3CH2CN 
C)  CH3CO2CH2CH3 
D)  CH3CH2SCH3

Exam 12: Infrared Spectroscopy and Mass Spectrometry

Account for fragments having a m/z value of 45 and 55 in the mass spectrum of 2-hexanol by drawing structures of the fragments.

What functional groups are represented in the following IR spectrum?

The region of the IR spectrum which generally contains the complex bending vibrations is called the ________ region of the spectrum.

What effect does conjugation typically have on the frequency at which absorption by C C occurs?

Which compound would show a larger than usual M+2 peak in the mass spectrum?

Which compound would be expected to show intense IR absorption at 3363, 3185, 1660 cm-1?

How could you tell if the hydrogenation of 2-pentene to pentane was complete?

Which of the following compounds has the lowest carbonyl stretching frequency?

Which compound would be expected to show an IR absorption at 3300 cm-1?

Which of the following compounds would contain characteristic IR stretches at 3300 and 2200 cm-1?

Could pentane and heptane easily be distinguished by IR spectroscopy?

Which has a lower characteristic stretching frequency, the C O bond or the C-O bond? Explain briefly.

Absorption of what type of electromagnetic radiation results in transitions among allowed nuclear magnetic spin states?

Which region of the electromagnetic spectrum, radio or visible, is characterized by waves of shorter wavelength?

Which compound would be expected to show intense IR absorption at 2250 cm-1?

In which unit is frequency measured?

How could IR spectroscopy be used to distinguish between the following pair of compounds? CH3COCH CHCH2CH3 and CH3COCH2CH2CH CH2

How could IR spectroscopy be used to distinguish between the following pair of compounds? CH3OCH2CH3 and CH3CH2CH2OH

Deduce a possible structure for the compound with the IR absorptions below. C5H8O: 2950, 1750 cm-1

Which compound would be expected to show intense IR absorption at 1746 cm-1?

Structure and Bonding

Acids and Bases; Functional Groups

Structure and Stereochemistry of Alkanes

The Study of Chemical Reactions

Stereochemistry

Alkyl Halides; Nucleophilic Substitution

Structure and Synthesis of Alkenes; Elimination

Reactions of Alkenes

Structure and Synthesis of Alcohols

Reactions of Alcohols

Nuclear Magnetic Resonance Spectroscopy

Ethers, Epoxides, and Thioethers

Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy

Aromatic Compounds

Reactions of Aromatic Compounds

Ketones and Aldehydes

Amines

Carboxylic Acids

Carboxylic Acid Derivatives

Condensations and Alpha Substitutions of Carboxyl Compounds

Carbohydrates and Nucleic Acids

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Which compound would be expected to show intense IR absorption at 3363, 3185, 1660 cm^-1?

Which compound would be expected to show an IR absorption at 3300 cm^-1?

Which of the following compounds would contain characteristic IR stretches at 3300 and 2200 cm^-1?

Which compound would be expected to show intense IR absorption at 2250 cm^-1?

How could IR spectroscopy be used to distinguish between the following pair of compounds? CH₃COCH CHCH₂CH₃ and CH₃COCH₂CH₂CH CH₂

How could IR spectroscopy be used to distinguish between the following pair of compounds? CH₃OCH₂CH₃ and CH₃CH₂CH₂OH

Deduce a possible structure for the compound with the IR absorptions below. C₅H₈O: 2950, 1750 cm^-1

Which compound would be expected to show intense IR absorption at 1746 cm^-1?