Question 1

Predict the molecular formula of the compound represented below based on the MS data given. 6H12 B) C5H24 C) C4H6O2 D) C3H8O2 E) C5H8O" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  C6H12
B)  C5H24
C)  C4H6O2
D)  C3H8O2
E)  C5H8OF) A) and D)
G) A) and C)

Question 2

Is the λmax of phenol in aqueous solution affected by the pH of the solution? If so, explain how and why λmax changes.

Accepted Answer

As the pH of the solution increases, an ...

Question 3

Which molecule below has a significant band in the 1720 - 1780 cm-1 range of its IR spectrum?

Accepted Answer

A)  CH3CH2CH2OH
B)  CH3C≡CCH2CH3
C)  CH3CH2CH(NH2) CH3
D)  (CH3) 3N
E)  CH3CO2CH2CH3F) A) and C)
G) A) and B)

Question 4

In the mass spectrum of bromoform, CHBr3, molecular ion peaks appear at m/z 250, 251, 252, and 253? What is the ratio of the intensities of these peaks?

Accepted Answer

A)  1:1:1:1
B)  1:2:2:1
C)  1:3:3:1
D)  2:3:3:2
E)  3:2:2:3F) B) and C)
G) A) and B)

Question 5

Which of the following is not a common bending vibration of a CH2 group?

Accepted Answer

A)  flip
B)  rock
C)  scissor
D)  twist
E)  wagF) A) and C)
G) None of the above

Question 6

Ethyl acetate has the structure CH3CO2CH2CH3. Which set of m/z peaks is most consistent with this structure?

Accepted Answer

A)  88, 73, 43
B)  88, 76, 45
C)  88, 73, 45
D)  88, 76, 43
E)  88, 72, 70, 44F) B) and E)
G) C) and D)

Question 7

In the mass spectrum of 2-chloropropane, what is the m/z of the molecular ion peak of greatest intensity?

Accepted Answer

A)  63
B)  76
C)  78
D)  80
E)  82F) All of the above
G) D) and E)

Question 8

The mass spectra of alcohols often fail to exhibit detectable M peaks but instead show relatively large ________ peaks.

Accepted Answer

A)  M+1
B)  M+2
C)  M-16
D)  M-17
E)  M-18F) B) and D)
G) A) and D)

Question 9

Which of the following m/z values is the molecular ion for 2-butanone?

Accepted Answer

A)  15
B)  29
C)  43
D)  57
E)  72F) A) and B)
G) B) and D)

Question 10

Which compound would be expected to show intense IR absorption at 1715 cm-1?

Accepted Answer

A)  CH3CH2CO2H
B)  1-hexene
C)  2-methylhexane
D)  CH3CH2CH2NH2E) C) and D)
F) B) and C)

Question 11

Which compound would be expected to show intense IR absorption at 2710 and 1705 cm-1?

Accepted Answer

A)  CH3COCH2CH3
B)  PhCOCH3
C)  PhCHO
D)  CH2   -1? 
A)  CH3COCH2CH3 
B)  PhCOCH3 
C)  PhCHO 
D)  CH2     CHCOCH3" class="answers-bank-image d-inline" rel="preload" > CHCOCH3E) B) and D)
F) None of the above

Question 12

Which color is observed when a sample absorbs light at 650 nm?

Accepted Answer

A)  yellow
B)  orange
C)  red
D)  violet
E)  greenish-blueF) C) and D)
G) B) and D)

Question 13

How many centimeters (cm) are there in one micrometer (μm) ?

Accepted Answer

A)  10-6
B)  10-3
C)  10-5
D)  10-8
E)  10-4F) A) and E)
G) C) and D)

Question 14

Which molecule below has two significant bands in the IR at 2720 cm-1 and 2820 cm-1 (medium) ?

Accepted Answer

A)  CH3COCH2CH
B)  CH3CH2CO2CH3
C)  CH2=CHCH2CH3
D)  CH3CH2CH2CHO
E)  CH3CH2CH2OHF) A) and B)
G) B) and C)

Question 15

Provide the structure of the two ions which result when the molecular ion of 2-methoxypentane undergoes fragmentation by

Accepted Answer

+ +
CH₃CH₂CH₂CH

_TB1830...

Question 16

Identify the compound that has a formula of C3H6O with a stretching vibration at 1050 cm-1 and an absorption band at 3400 cm-1, but no doublet at 1380 cm-1.

Accepted Answer

A)  1-propanol
B)  2-propanol
C)  ethyl methyl ether
D)  propen-1-ol
E)  propen-2-olF) C) and E)
G) A) and B)

Question 17

Which of the following solvents is best used in infrared spectroscopy?

Accepted Answer

A)  I
B)  II
C)  III
D)  IV
E)  VF) None of the above
G) C) and D)

Question 18

2-Methylhexane shows an intense peak in the mass spectrum at m/z = 43. Propose a likely structure for this fragment.

Accepted Answer

The answer of 2-Methylhexane shows an intense peak in the...

Question 19

Which of the following statements is not true about electromagnetic radiation?

Accepted Answer

A)  The velocity of light is directly proportional to the energy.
B)  All molecules absorb electromagnetic radiation at some frequency.
C)  Frequency is inversely proportional to wavelength.
D)  Energy is directly proportional to frequency.
E)  Energy is inversely proportional to wavelength.F) C) and D)
G) D) and E)

Question 20

Which molecule below has a significant band in the IR at 3300 cm-1 (medium and sharp) ?

Accepted Answer

A)  1-pentene
B)  cyclohexane
C)  2-heptyne
D)  1-pentyne
E)  diethyl etherF) D) and E)
G) C) and D)

Exam 14: Mass Spectrometry, Infrared Spectroscopy, and Uvvis Spectroscopy

Which molecule below has a significant band in the 1720 - 1780 cm-1 range of its IR spectrum?

Correct AnswerverifiedShow Answer

Which color is observed when a sample absorbs light at 650 nm?

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Is the λmax of phenol in aqueous solution affected by the pH of the solution? If so, explain how and why λmax changes.

Correct AnswerverifiedAs the pH of the solution increases, an ...View AnswerShow Answer

Which compound would be expected to show intense IR absorption at 1715 cm-1?

Correct AnswerverifiedShow Answer

2-Methylhexane shows an intense peak in the mass spectrum at m/z = 43. Propose a likely structure for this fragment.

Correct AnswerverifiedShow Answer

Identify the compound that has a formula of C3H6O with a stretching vibration at 1050 cm-1 and an absorption band at 3400 cm-1, but no doublet at 1380 cm-1.

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Ethyl acetate has the structure CH3CO2CH2CH3. Which set of m/z peaks is most consistent with this structure?

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Predict the molecular formula of the compound represented below based on the MS data given.

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How many centimeters (cm) are there in one micrometer (μm) ?

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Which of the following m/z values is the molecular ion for 2-butanone?

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Which of the following is not a common bending vibration of a CH2 group?

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Which of the following solvents is best used in infrared spectroscopy?

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The mass spectra of alcohols often fail to exhibit detectable M peaks but instead show relatively large ________ peaks.

Correct AnswerverifiedShow Answer

In the mass spectrum of 2-chloropropane, what is the m/z of the molecular ion peak of greatest intensity?

Correct AnswerverifiedShow Answer

Which compound would be expected to show intense IR absorption at 2710 and 1705 cm-1?

Correct AnswerverifiedShow Answer

Provide the structure of the two ions which result when the molecular ion of 2-methoxypentane undergoes fragmentation by

Correct Answerverified+ +CH3CH2CH2CH _TB1830...View AnswerShow Answer

Which molecule below has two significant bands in the IR at 2720 cm-1 and 2820 cm-1 (medium) ?

Correct AnswerverifiedShow Answer

In the mass spectrum of bromoform, CHBr3, molecular ion peaks appear at m/z 250, 251, 252, and 253? What is the ratio of the intensities of these peaks?

Correct AnswerverifiedShow Answer

Which of the following statements is not true about electromagnetic radiation?

Correct AnswerverifiedShow Answer

Which molecule below has a significant band in the IR at 3300 cm-1 (medium and sharp) ?

Correct AnswerverifiedShow Answer

Which molecule below has a significant band in the 1720 - 1780 cm^-1 range of its IR spectrum?

Correct Answer
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Is the λ_max of phenol in aqueous solution affected by the pH of the solution? If so, explain how and why λ_max changes.

Correct Answer
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As the pH of the solution increases, an ...
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Which compound would be expected to show intense IR absorption at 1715 cm^-1?

Correct Answer
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Identify the compound that has a formula of C₃H₆O with a stretching vibration at 1050 cm^-1 and an absorption band at 3400 cm^-1, but no doublet at 1380 cm^-1.

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Ethyl acetate has the structure CH₃CO₂CH₂CH₃. Which set of m/z peaks is most consistent with this structure?

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Which of the following is not a common bending vibration of a CH₂ group?

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Which compound would be expected to show intense IR absorption at 2710 and 1705 cm^-1?

Correct Answer
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+ +
CH₃CH₂CH₂CH _TB1830...
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Which molecule below has two significant bands in the IR at 2720 cm^-1 and 2820 cm^-1(medium) ?

Correct Answer
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In the mass spectrum of bromoform, CHBr₃, molecular ion peaks appear at m/z 250, 251, 252, and 253? What is the ratio of the intensities of these peaks?

Correct Answer
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Which molecule below has a significant band in the IR at 3300 cm^-1 (medium and sharp) ?

Correct Answer
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