Question 1

Which of the following species has a characteristic broad absorption at 3200-3500 cm-1 in its IR spectrum?

Accepted Answer

A) PhCH2CN 
B) PhCH2N(CH3)2 
C) PhCH2CO2CH3 
D) PhCH2CH2OH 
E) PhCH2OCH3 
A) PhCH2CN 
B) PhCH2N(CH3)2 
C) PhCH2CO2CH3 
D) PhCH2CH2OH 
E) PhCH2OCH3

Question 2

Which of the following species has a characteristic absorption at 3300 cm-1 in its IR spectrum?

Accepted Answer

A) (CH3)2CHCCH 
B) (CH3)2CHN(CH3)2 
C) (CH3)2CHCCCH3 
D) (CH3)2CHCH   CH2 
E) (CH3)2CHCO2CH3 
A) (CH3)2CHCCH 
B) (CH3)2CHN(CH3)2 
C) (CH3)2CHCCCH3 
D) (CH3)2CHCH   CH2 
E) (CH3)2CHCO2CH3

Question 3

In the UV-visible spectrum of (E)-1,3,5-hexatriene,the lowest energy absorption corresponds to

Accepted Answer

A) a π to π* transition. 
B) a σ to π* transition. 
C) a π to σ* transition. 
D) a σ to σ* transition. 
E) a σ to π transition. 
A) a π to π* transition. 
B) a σ to π* transition. 
C) a π to σ* transition. 
D) a σ to σ* transition. 
E) a σ to π transition.

Question 4

Which molecule below has two significant bands (medium and broad)in the 3300 - 3500 cm-1 range of its IR spectrum?

Accepted Answer

A) (CH3)3N 
B) CH3CH2NHCH3 
C) CH3CH2NH2 
D) CH3CON(CH3)2 
E) CH3OCH2CH2N(CH3)2 
A) (CH3)3N 
B) CH3CH2NHCH3 
C) CH3CH2NH2 
D) CH3CON(CH3)2 
E) CH3OCH2CH2N(CH3)2

Question 5

Deduce a possible structure for the compound with the IR absorptions below.
C3H5N: 3000,2250 cm-1

Accepted Answer

Question 6

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

Accepted Answer

+ + CH₃CH₂CH

Question 7

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 i

Question 8

Which molecule below has a significant band in the IR at 2220 cm-1 (medium)?

Accepted Answer

A) CH3CH2CH2OH 
B) CH3C   CCH2CH3 
C) CH3CH2CH(NH2)CH3 
D) (CH3)3N 
E) CH3CO2CH2CH3 
A) CH3CH2CH2OH 
B) CH3C   CCH2CH3 
C) CH3CH2CH(NH2)CH3 
D) (CH3)3N 
E) CH3CO2CH2CH3

Question 9

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) 82 
A) 63 
B) 76 
C) 78 
D) 80 
E) 82

Question 10

Give the ion that corresponds a m/z ratio of 31 in a mass spectrum of 1-butanol.

Accepted Answer

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

Question 11

In the mass spectrum of 1,2-dichloroethane,what is the m/z of the molecular ion peak of greatest intensity?

Accepted Answer

A) 94 
B) 96 
C) 98 
D) 100 
E) 102 
A) 94 
B) 96 
C) 98 
D) 100 
E) 102

Question 12

How would you verify the completion of the following reaction by IR spectroscopy?

Accepted Answer

A broad peak due to O-H stretc

Question 13

Explain how hydrogen bonding affects the shape of O-H and N-H absorption bands in IR spectra.

Accepted Answer

O-H and N-H bands are generally quite br

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 or...

Question 15

At what wavenumber will the C-H stretch involving an sp carbon appear?

Accepted Answer

A) 2700 cm-1 
B) 2900 cm-1 
C) 3100 cm-1 
D) 3300 cm-1 
E) 3500 cm-1 
A) 2700 cm-1 
B) 2900 cm-1 
C) 3100 cm-1 
D) 3300 cm-1 
E) 3500 cm-1

Question 16

Describe the molecular ion region in the mass spectrum of CH3CH2Br.

Accepted Answer

The natural abundance of the i

Question 17

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

Accepted Answer

A) CH3CCCH3 
B) butane 
C) 1-butene 
D) CH3CH2CCH 
A) CH3CCCH3 
B) butane 
C) 1-butene 
D) CH3CH2CCH

Question 18

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

Accepted Answer

C-D; heavier atoms i

Question 19

Which compound's C≡C IR band is weakest,1-butyne,2-pentyne,or 3-hexyne? Why?

Accepted Answer

The C @#IMG-DLM& C band of 3-hexyne is w

Question 20

How would you verify the completion of the following reaction by IR spectroscopy?

Accepted Answer

A peak due to C @#IMG-DLM& C stretch bet

Exam 13: Mass Spectrometry,infrared Spectroscopy,and Uvvis Spectroscopy

Which of the following species has a characteristic broad absorption at 3200-3500 cm-1 in its IR spectrum?

Which of the following species has a characteristic absorption at 3300 cm-1 in its IR spectrum?

In the UV-visible spectrum of (E)-1,3,5-hexatriene,the lowest energy absorption corresponds to

Which molecule below has two significant bands (medium and broad)in the 3300 - 3500 cm-1 range of its IR spectrum?

Deduce a possible structure for the compound with the IR absorptions below. C3H5N: 3000,2250 cm-1

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

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

Which molecule below has a significant band in the IR at 2220 cm-1 (medium)?

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

Give the ion that corresponds a m/z ratio of 31 in a mass spectrum of 1-butanol.

In the mass spectrum of 1,2-dichloroethane,what is the m/z of the molecular ion peak of greatest intensity?

How would you verify the completion of the following reaction by IR spectroscopy?

Explain how hydrogen bonding affects the shape of O-H and N-H absorption bands in IR spectra.

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

At what wavenumber will the C-H stretch involving an sp carbon appear?

Describe the molecular ion region in the mass spectrum of CH3CH2Br.

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

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

Which compound's C≡C IR band is weakest,1-butyne,2-pentyne,or 3-hexyne? Why?

How would you verify the completion of the following reaction by IR spectroscopy?

Remembering General Chemistry: Electronic Structure and Bonding

Acids and Bases: Central to Understanding Organic Chemistry

An Introduction to Organic Compounds: Nomenclature, physical Properties, and Structure

Isomers: the Arrangement of Atoms in Space

Alkenes: Structure,nomenclature,and an Introduction to Reactivity - Thermodynamics and Kinetics

The Reactions of Alkenes - the Stereochemistry of Addition Reactions

The Reactions of Alkynes - Introduction to Multistep Synthesis

Delocalized Electrons: Their Effect on Stability, pka, and the Products of a Reaction - Aromaticity and Electronic Effects: an Introduction to the Reactions of Benzene

Substitution and Elimination Reactions of Alkyl Halides

Reactions of Alcohols, ethers, epoxides, amines and Sulfur-Containing Compounds

Organometallic Compounds

Radicals

Nmr Spectroscopy

Reactions of Carboxylic Acids and Carboxylic Acid Derivatives

Reactions of Aldehydes and Ketones

Reactions at the Α-Carbon

Reactions of Benzene and Substituted Benzenes

More About Amines - Reactions of Heterocylic Compounds

The Organic Chemistry of Carbohydrates

Amino Acids,peptides,and Proteins

Catalysis in Organic Reactions and in Enzymatic Reactions

The Organic Chemistry of the Coenzymes, compounds Derived From Vitamins

The Organic Chemistry of the Metabolic Pathways

The Organic Chemistry of Lipids

The Chemistry of the Nucleic Acids

Synthetic Polymers

Pericyclic Reactions

Filters

Which of the following species has a characteristic broad absorption at 3200-3500 cm^-1 in its IR spectrum?

Which of the following species has a characteristic absorption at 3300 cm^-1 in its IR spectrum?

Which molecule below has two significant bands (medium and broad)in the 3300 - 3500 cm^-1 range of its IR spectrum?

Deduce a possible structure for the compound with the IR absorptions below. C₃H₅N: 3000,2250 cm^-1

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

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.

Which molecule below has a significant band in the IR at 2220 cm^-1 (medium)?

Describe the molecular ion region in the mass spectrum of CH₃CH₂Br.

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