Question 1

Assume you are carrying out the conversion of 1-bromobutane to butan-1-ol. How could you use IR spectroscopy to determine when the reaction is complete?

Accepted Answer

The infrared spectrum of the starting br

Question 2

Which of the following statements best describes the base peak in a mass spectrum?

Accepted Answer

A)  The peak from the most stable radical. 
B)  The peak from the species that has the isotope with the highest atomic number. 
C)  The peak of highest intensity. 
D)  The peak from the molecule minus an electron. 
E)  The M +1 peak 
A)  The peak from the most stable radical. 
B)  The peak from the species that has the isotope with the highest atomic number. 
C)  The peak of highest intensity. 
D)  The peak from the molecule minus an electron. 
E)  The M +1 peak

Question 3

Which of the following compounds gives an infrared spectrum with a peak at ~1750 cm-1, but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1?

Accepted Answer

A)   
B)   
C)   
D)   
A)   
B)   
C)   
D)

Question 4

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled S1U1P113S1S1P0C NMR spectra.
-Number of signals:

Accepted Answer

The answer of Instructions: For each of the compounds below...

Question 5

Consider the compound below:   
a)At what approximate positions might the compound show IR absorptions? 
b)How would this spectrum differ from that of cyclohexanol?

Accepted Answer

a)This compound should show a characteri

Question 6

Instructions: The following questions pertain to the charting of NMR spectra. MATCH a term to each description below. Place the letter of the term in the blank to the left of the description.

-Refer to instructions. __________ The NMR charts are calibrated using an arbitrary scale that is divided into __________ units.

Accepted Answer

A) TMS 
B) high-field or upfield side 
C) MHz 
D) delta $\delta$ 
E) low-field or downfield side
F)chemical shift
G)specific absorption 
A) TMS 
B) high-field or upfield side 
C) MHz 
D) delta $\delta$ 
E) low-field or downfield side
F)chemical shift
G)specific absorption

Question 7

Instructions: Predict the splitting patterns you would expect for each proton in the molecules below:
-Predict:

Accepted Answer

The answer of Instructions: Predict the splitting patterns you would...

Question 8

A compound with the molecular formula C6H4ClBr produces only two doublets in the 1H NMR spectrum.
a)Propose a structure for this compound.
b)How many signals would be present in the 13CNMR for this structure?

Accepted Answer

Question 9

Which of the following bonds undergoes stretching at the highest frequency?

Accepted Answer

A)  C=O 
B)  C-O 
C)  C=C 
D)  C-C 
A)  C=O 
B)  C-O 
C)  C=C 
D)  C-C

Question 10

Instructions: The following questions pertain to the charting of NMR spectra. MATCH a term to each description below. Place the letter of the term in the blank to the left of the description.

-Refer to instructions. __________ The exact place on the chart at which a nucleus absorbs is called its __________.

Accepted Answer

A) TMS 
B) high-field or upfield side 
C) MHz 
D) delta $\delta$ 
E) low-field or downfield side
F)chemical shift
G)specific absorption 
A) TMS 
B) high-field or upfield side 
C) MHz 
D) delta $\delta$ 
E) low-field or downfield side
F)chemical shift
G)specific absorption

Question 11

Instructions: Select the most reasonable formula for the compounds with the following mass spectral data.
-Refer to instructions. MS1U1P1+S1S1P0 at m/z = 216

Accepted Answer

A)  CS1U1B16S1U1B0HS1U1B113S1U1B0OCl 
B)  CS1U1B14S1U1B0HS1U1B18S1U1B0BrS1U1B12S1U1B0 
C)  CS1U1B110S1U1B0HS1U1B116S1U1B0 
D)  CS1U1B19S1U1B0HS1U1B112S1U1B0O 
A)  CS1U1B16S1U1B0HS1U1B113S1U1B0OCl 
B)  CS1U1B14S1U1B0HS1U1B18S1U1B0BrS1U1B12S1U1B0 
C)  CS1U1B110S1U1B0HS1U1B116S1U1B0 
D)  CS1U1B19S1U1B0HS1U1B112S1U1B0O

Question 12

Instructions: Match each of the following groups of bond-types to the region of the infrared spectrum in which their absorptions occur.

-N-H, C-H, and O-H stretching and bending motions.

Accepted Answer

A) 4000 to 2500 cm-1 
B) 2500 to 2000 cm-1 
C) 2000 to 1500 cm-1 
D) below 1500 cm-1 
A) 4000 to 2500 cm-1 
B) 2500 to 2000 cm-1 
C) 2000 to 1500 cm-1 
D) below 1500 cm-1

Question 13

The amount of energy in infrared light corresponds to:

Accepted Answer

A)  the amount of energy needed to promote one electron from a bonding to an antibonding molecular orbital 
B)  the amount of energy needed to fragment a molecule 
C)  the amount of energy needed to strip a molecule of one electron to generate a cation radical 
D)  the amount of energy needed to increase certain molecular motions, such as bond vibrations, in organic molecules 
A)  the amount of energy needed to promote one electron from a bonding to an antibonding molecular orbital 
B)  the amount of energy needed to fragment a molecule 
C)  the amount of energy needed to strip a molecule of one electron to generate a cation radical 
D)  the amount of energy needed to increase certain molecular motions, such as bond vibrations, in organic molecules

Question 14

Nuclear magnetic resonance spectroscopy provides information about a molecule's:

Accepted Answer

A)  conjugated pi electron system 
B)  size and formula. 
C)  carbon-hydrogen framework. 
D)  functional groups. 
A)  conjugated pi electron system 
B)  size and formula. 
C)  carbon-hydrogen framework. 
D)  functional groups.

Question 15

Which of the following compounds gives a 1H NMR spectrum consisting of only two singlets?

Accepted Answer

A)  CH3OCH2CH2OCH2CH3 
B)  CH3OCH2CH2CH2CH2OH 
C)  CH3OC(CH3)2OCH3 
D)  CH3OCH2CH(CH3)OCH3 
A)  CH3OCH2CH2OCH2CH3 
B)  CH3OCH2CH2CH2CH2OH 
C)  CH3OC(CH3)2OCH3 
D)  CH3OCH2CH(CH3)OCH3

Question 16

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s).   (Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/)
-Refer to instructions. What peak represents the base peak?

Accepted Answer

The peak a

Question 17

Which feature in the 1H NMR spectrum provides information about the electronic environment of the protons in a compound?

Accepted Answer

A)  number of signals 
B)  integration of signals 
C)  splitting of signals 
D)  chemical shift 
A)  number of signals 
B)  integration of signals 
C)  splitting of signals 
D)  chemical shift

Question 18

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s).   (Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/)
-Refer to instructions. What peak represents M+?

Accepted Answer

The peak a

Question 19

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled S1U1P113S1S1P0C NMR spectra.
-Number of signals:

Accepted Answer

The answer of Instructions: For each of the compounds below...

Question 20

Which of the following bonds gives rise to a strong absorbance near 1700 cm-1 in the infrared spectrum?

Accepted Answer

A)  C=O 
B)  C-O 
C)  C=C 
D)  C-C 
A)  C=O 
B)  C-O 
C)  C=C 
D)  C-C

Assume you are carrying out the conversion of 1-bromobutane to butan-1-ol. How could you use IR spectroscopy to determine when the reaction is complete?

Which of the following statements best describes the base peak in a mass spectrum?

Which of the following compounds gives an infrared spectrum with a peak at ~1750 cm^-¹, but no significant peaks at 3000-3500 cm^-¹ or 1050-1250 cm^-¹?

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled ¹³C NMR spectra. -Number of signals:

Consider the compound below: a)At what approximate positions might the compound show IR absorptions? b)How would this spectrum differ from that of cyclohexanol?

Instructions: The following questions pertain to the charting of NMR spectra. MATCH a term to each description below. Place the letter of the term in the blank to the left of the description. -Refer to instructions. The NMR charts are calibrated using an arbitrary scale that is divided into units.

Instructions: Predict the splitting patterns you would expect for each proton in the molecules below: -Predict:

A compound with the molecular formula C₆H₄ClBr produces only two doublets in the ¹H NMR spectrum. a)Propose a structure for this compound. b)How many signals would be present in the ¹³CNMR for this structure?

Which of the following bonds undergoes stretching at the highest frequency?

Instructions: The following questions pertain to the charting of NMR spectra. MATCH a term to each description below. Place the letter of the term in the blank to the left of the description. -Refer to instructions. The exact place on the chart at which a nucleus absorbs is called its .

Instructions: Select the most reasonable formula for the compounds with the following mass spectral data. -Refer to instructions. M⁺ at m/z = 216

Instructions: Match each of the following groups of bond-types to the region of the infrared spectrum in which their absorptions occur. -N-H, C-H, and O-H stretching and bending motions.

The amount of energy in infrared light corresponds to:

Nuclear magnetic resonance spectroscopy provides information about a molecule's:

Which of the following compounds gives a ¹H NMR spectrum consisting of only two singlets?

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). (Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/) -Refer to instructions. What peak represents the base peak?

Which feature in the ¹H NMR spectrum provides information about the electronic environment of the protons in a compound?

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). (Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/) -Refer to instructions. What peak represents M⁺?

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled ¹³C NMR spectra. -Number of signals:

Which of the following bonds gives rise to a strong absorbance near 1700 cm^-¹ in the infrared spectrum?

Structure and Bonding:acids and Bases

Alkanes: the Nature of Organic Compounds

Alkenes and Alkynes: the Nature of Organic Reactions

Reactions of Alkenes and Alkynes

Aromatic Compounds

Sterechemistry at Tetrahedral Centers

Organohalides: Nucleophilic Substitutions and Eliminations

Alcohols, Phenols, Ethers, and Their Sulfur Analogs

Aldehydes and Ketones: Nucleophilic Addition Reactions

Carboxylic Acids and Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution Reactions and Condensation Reactions

Amines

Biomolecules: Carbohydrates

Biomolecules: Amino Acids, Peptides, and Proteins

Biomolecules: Lipids and Nucleic Acids

The Organic Chemistry of Metabolic Pathways

Filters

Exam 13: Structure Determination

Assume you are carrying out the conversion of 1-bromobutane to butan-1-ol. How could you use IR spectroscopy to determine when the reaction is complete?

Which of the following statements best describes the base peak in a mass spectrum?

Which of the following compounds gives an infrared spectrum with a peak at ~1750 cm-1, but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1?

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled 13C NMR spectra. -Number of signals:

Consider the compound below: a)At what approximate positions might the compound show IR absorptions? b)How would this spectrum differ from that of cyclohexanol?

Instructions: Predict the splitting patterns you would expect for each proton in the molecules below: -Predict:

A compound with the molecular formula C6H4ClBr produces only two doublets in the 1H NMR spectrum. a)Propose a structure for this compound. b)How many signals would be present in the 13CNMR for this structure?

Which of the following bonds undergoes stretching at the highest frequency?

Instructions: Select the most reasonable formula for the compounds with the following mass spectral data. -Refer to instructions. M+ at m/z = 216

Instructions: Match each of the following groups of bond-types to the region of the infrared spectrum in which their absorptions occur. -N-H, C-H, and O-H stretching and bending motions.

The amount of energy in infrared light corresponds to:

Nuclear magnetic resonance spectroscopy provides information about a molecule's:

Which of the following compounds gives a 1H NMR spectrum consisting of only two singlets?

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). (Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/) -Refer to instructions. What peak represents the base peak?

Which feature in the 1H NMR spectrum provides information about the electronic environment of the protons in a compound?

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). (Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/) -Refer to instructions. What peak represents M+?

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled 13C NMR spectra. -Number of signals:

Which of the following bonds gives rise to a strong absorbance near 1700 cm-1 in the infrared spectrum?

Structure and Bonding:acids and Bases

Alkanes: the Nature of Organic Compounds

Alkenes and Alkynes: the Nature of Organic Reactions

Reactions of Alkenes and Alkynes

Aromatic Compounds

Sterechemistry at Tetrahedral Centers

Organohalides: Nucleophilic Substitutions and Eliminations

Alcohols, Phenols, Ethers, and Their Sulfur Analogs

Aldehydes and Ketones: Nucleophilic Addition Reactions

Carboxylic Acids and Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution Reactions and Condensation Reactions

Amines

Biomolecules: Carbohydrates

Biomolecules: Amino Acids, Peptides, and Proteins

Biomolecules: Lipids and Nucleic Acids

The Organic Chemistry of Metabolic Pathways

Filters

Which of the following compounds gives an infrared spectrum with a peak at ~1750 cm^-¹, but no significant peaks at 3000-3500 cm^-¹ or 1050-1250 cm^-¹?

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled ¹³C NMR spectra. -Number of signals:

A compound with the molecular formula C₆H₄ClBr produces only two doublets in the ¹H NMR spectrum. a)Propose a structure for this compound. b)How many signals would be present in the ¹³CNMR for this structure?

Instructions: Select the most reasonable formula for the compounds with the following mass spectral data. -Refer to instructions. M⁺ at m/z = 216

Which of the following compounds gives a ¹H NMR spectrum consisting of only two singlets?

Which feature in the ¹H NMR spectrum provides information about the electronic environment of the protons in a compound?

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). (Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/) -Refer to instructions. What peak represents M⁺?

Instructions: For each of the compounds below tell how many signals you would expect the molecule to have in its normal, broadband decoupled ¹³C NMR spectra. -Number of signals:

Which of the following bonds gives rise to a strong absorbance near 1700 cm^-¹ in the infrared spectrum?