Question 1

Following are the IR spectrum and mass spectrum of an unknown compound. Propose a structure for the unknown compound.   SDBS:

Accepted Answer

The answer of Following are the IR spectrum and mass...

Question 2

Rank absorption of the indicated bonds in decreasing (highest to lowest)  order of wavenumber. II>I B)  I>II>III C)  II>I>III D)  III>I>II E)  none of these" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   III>II>I
B)   I>II>III
C)   II>I>III
D)   III>I>II
E)   none of theseF) C) and D)
G) A) and E)

Question 3

Which of the following will produce (M+2) + . peak one third the intensity of M+ .  peak?

Accepted Answer

A)   nitrogen
B)   chlorine
C)   bromine
D)   oxygen
E)   B & CF) C) and E)
G) A) and B)

Question 4

For the following reaction, which of the following change(s)  in the IR spectrum is consistent with conversion of the reactant to the product? -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" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

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 theseF) B) and E)
G) D) and E)

Question 5

Calculate the degree of unsaturation for C14H14N2O.

Accepted Answer

A)   4
B)   6
C)   8
D)   10
E)   9F) A) and D)
G) B) and C)

Question 6

Which of the following is true about the IR spectrum of the compound shown below? -1 & 2150 cm-1 B)  absorptions at 1800 cm-1 & 2150 cm-1 C)  absorptions at 1720 cm-1 & 2250 cm-1 D)  absorptions at 1800 cm-1 & 2250 cm-1 E)  absorptions at 1650 cm-1 & 2150 cm-1" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   absorptions at 1720 cm-1 & 2150 cm-1
B)   absorptions at 1800 cm-1 & 2150 cm-1
C)   absorptions at 1720 cm-1 & 2250 cm-1
D)   absorptions at 1800 cm-1 & 2250 cm-1
E)   absorptions at 1650 cm-1 & 2150 cm-1F) None of the above
G) B) and C)

Question 7

The C-O absorption in carboxylic acids appears around 1250cm-1, where as the C-O absortion in alcohol appears around 1050cm-1. Explain why.

Accepted Answer

The C-O bond in carboxylic aci...

Question 8

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

Accepted Answer

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)   all of theseF) B) and D)
G) All of the above

Question 9

Which of the following is expected to be the base peak in the mass spectrum of pentanal?

Accepted Answer

A)   29
B)   41
C)   44
D)   58
E)   86F) A) and C)
G) A) and B)

Question 10

Which of the following bonds has the strongest absorption?

Accepted Answer

A)   C=N
B)   C ≡ \equiv≡ C
C)   C=O
D)   sp2C-H
E)   C-O F) D) and E)
G) B) and E)

Question 11

Provide a molecular formula that is consistent with the following mass spectrum data.
M+ .  at m/z= 136, relative height=65.6%
(M+1)+ .  at m/z= 137, relative height=6.2%

Accepted Answer

C<sub>9</s...

Question 12

For each of the following IR spectra determine if it 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.

Accepted Answer

I: seconda...

Question 13

Which of the following is initially produced when a compound is bombarded with high energy electrons?

Accepted Answer

A)   anion
B)   free radical
C)   radical cation
D)   cation
E)   none of theseF) B) and D)
G) C) and D)

Question 14

Which of the following vibrations are observed in IR spectroscopy?

Accepted Answer

A)   stetching
B)   rotational
C)   bending
D)   A & B
E)   A & CF) A) and E)
G) C) and D)

Question 15

Absorption of _______radiation results in vibrational excitation of the bonds in a compound.

Accepted Answer

A)   UV
B)   Microwave
C)   IR
D)   Visible
E)   x-rayF) C) and D)
G) A) and B)

Question 16

Which of the following is expected to be the base peak in the mass spectrum of CH3(CH2) 4OH?

Accepted Answer

A)   88
B)   55
C)   42
D)   31
E)   none of theseF) B) and D)
G) A) and C)

Question 17

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

Accepted Answer

Question 18

Which of the following compounds will show two absorptions at 2700 cm-1 and at 2800 cm-1 along with the carbonyl absorption? -1 and at 2800 cm-1 along with the carbonyl absorption?   A)  I B)  II C)  III D)  IV E)  none of these" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   I
B)   II
C)   III
D)   IV
E)   none of theseF) B) and D)
G) A) and B)

Question 19

Which of the following compounds will produce a prominent (M-15)  peak in the mass spectrum?

Accepted Answer

A)   2-methylheptane
B)   1-heptanol
C)   heptanamine
D)   1-chloroheptane
E)   none of theseF) A) and D)
G) A) and E)

Question 20

In mass spectrometry, the cations are separated by their ______________.

Accepted Answer

mass to ch...

Exam 15: Infrared Spectroscopy and Mass Spectrometry

Calculate the degree of unsaturation for C14H14N2O.

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Which of the following compounds will show two absorptions at 2700 cm-1 and at 2800 cm-1 along with the carbonyl absorption?

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Which of the following bonds has the strongest absorption?

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The C-O absorption in carboxylic acids appears around 1250cm-1, where as the C-O absortion in alcohol appears around 1050cm-1. Explain why.

Correct AnswerverifiedThe C-O bond in carboxylic aci...View AnswerShow Answer

In mass spectrometry, the cations are separated by their ______________.

Correct Answerverifiedmass to ch...View AnswerShow Answer

Which of the following is true about the IR spectrum of the compound shown below?

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

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

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Which of the following is expected to be the base peak in the mass spectrum of pentanal?

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Which of the following is expected to be the base peak in the mass spectrum of CH3(CH2) 4OH?

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Which of the following is initially produced when a compound is bombarded with high energy electrons?

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

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Provide a molecular formula that is consistent with the following mass spectrum data. M+ . at m/z= 136, relative height=65.6% (M+1)+ . at m/z= 137, relative height=6.2%

Correct AnswerverifiedC9View AnswerShow Answer

Following are the IR spectrum and mass spectrum of an unknown compound. Propose a structure for the unknown compound. SDBS:

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Which of the following vibrations are observed in IR spectroscopy?

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Absorption of _______radiation results in vibrational excitation of the bonds in a compound.

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Which of the following will produce (M+2) + . peak one third the intensity of M+ . peak?

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For each of the following IR spectra determine if it 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.

Correct AnswerverifiedI: seconda...View AnswerShow Answer

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

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Which of the following compounds will produce a prominent (M-15) peak in the mass spectrum?

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Calculate the degree of unsaturation for C₁₄H₁₄N₂O.

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Which of the following compounds will show two absorptions at 2700 cm^-1 and at 2800 cm^-1 along with the carbonyl absorption?

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The C-O absorption in carboxylic acids appears around 1250cm^-1, where as the C-O absortion in alcohol appears around 1050cm^-1. Explain why.

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The C-O bond in carboxylic aci...
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mass to ch...
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Provide the structure of the major fragment that results when the molecular ion of (CH₃)₂CHCH₂CH₂NH₂ undergoes fragmentation.

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Which of the following is expected to be the base peak in the mass spectrum of CH₃(CH₂) ₄OH?

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Provide a molecular formula that is consistent with the following mass spectrum data. M⁺ ^. at m/z= 136, relative height=65.6% (M+1)⁺ ^. at m/z= 137, relative height=6.2%

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C_{9View Answer}

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Which of the following will produce (M+2) ⁺ ^. peak one third the intensity of M⁺ ^. peak?

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I: seconda...
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