Question 1

When a solution of an organic compound absorbs light whose wavelength is 700 nm,the solution appears

Accepted Answer

A) yellow. 
B) bluish-green. 
C) red. 
D) orange. 
E) purple. 
A) yellow. 
B) bluish-green. 
C) red. 
D) orange. 
E) purple. B

Question 2

What does "m/z" stand for and what does it mean?

Accepted Answer

The "m" stands for the mass and "z" for the charge.Since most fragments have a charge of +1,m/z is the molecular weight of the fragment.

Question 3

Deduce a possible structure for the compound with the IR absorptions below.
C4H8O: 3000,2800,2715,1715 cm-1

Accepted Answer

CH₃CH₂CH₂CHO

Question 4

Which compound's mass spectrum shows peaks at M,M+2,and M+4 whose abundances are in a ratio of 1:2:1?

Accepted Answer

A) cyclohexanol 
B) chlorocyclohexane 
C) 1,2-dichlorocyclohexane 
D) 1-bromopentane 
E) 1,5-dibromopentane 
A) cyclohexanol 
B) chlorocyclohexane 
C) 1,2-dichlorocyclohexane 
D) 1-bromopentane 
E) 1,5-dibromopentane

Question 5

How could IR spectroscopy be used to distinguish between the following pair of compounds?
(CH3)3N and CH3NHCH2CH3

Accepted Answer

N-H absorp

Question 6

How could you distinguish the mass spectrum of 2,2-dimethylpropane from that of isopentane?

Accepted Answer

The loss of a methyl from 2,2-dimethylpr

Question 7

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

Accepted Answer

O-H stretc

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

Question 9

A compound shows a molecular ion peak at m/z 167.The relative intensities of the M and M+1 peaks are 50.0 and 4.4 respectively.How many carbons are in each molecule of the compound?

Accepted Answer

The answer of A compound shows a molecular ion peak...

Question 10

How could IR spectroscopy be used to distinguish between the following pair of compounds?
HOCH2CH2CHO and CH3CH2CO2H

Accepted Answer

Carboxylic acid will

Question 11

Which compound has the lowest carbonyl absorption frequency in an infrared spectrum?

Accepted Answer

A) ester 
B) ketone 
C) amide 
D) aldehyde 
E) carboxylic acid 
A) ester 
B) ketone 
C) amide 
D) aldehyde 
E) carboxylic acid

Question 12

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) wag 
A) flip 
B) rock 
C) scissor 
D) twist 
E) wag

Question 13

Which of the following m/z values correspond to the molecular ion peak of the following compound?

Accepted Answer

A) 309 
B) 310 
C) 311 
D) 312 
E) 313 
A) 309 
B) 310 
C) 311 
D) 312 
E) 313

Question 14

Absorption of UV-visible energy by a molecule results in

Accepted Answer

A) vibrational transitions. 
B) electronic transitions. 
C) rotational transitions. 
D) nuclear transitions. 
E) none of the above. 
A) vibrational transitions. 
B) electronic transitions. 
C) rotational transitions. 
D) nuclear transitions. 
E) none of the above.

Question 15

Which of the following increases the absorbance of a solution of phenol in ethanol?

Accepted Answer

A) increasing the amount of phenol in the solution 
B) decreasing the amount of ethanol in the solution 
C) decreasing the light path through the solution 
D) both A and B 
E) both B and C 
A) increasing the amount of phenol in the solution 
B) decreasing the amount of ethanol in the solution 
C) decreasing the light path through the solution 
D) both A and B 
E) both B and C

Question 16

When a solution of an organic compound absorbs light whose wavelength is 400 nm,the solution appears

Accepted Answer

A) yellow. 
B) red. 
C) purple. 
D) blue. 
E) white. 
A) yellow. 
B) red. 
C) purple. 
D) blue. 
E) white.

Question 17

Which of the following is highest in energy per photon?

Accepted Answer

A) electromagnetic radiation with a wavenumber of 10-2 cm-1 
B) electromagnetic radiation with a frequency of 107 s-1 
C) electromagnetic radiation with a frequency of 105 s-1 
D) electromagnetic radiation with a wavelength of 10 cm 
E) electromagnetic radiation with a wavenumber of 106 cm-1 
A) electromagnetic radiation with a wavenumber of 10-2 cm-1 
B) electromagnetic radiation with a frequency of 107 s-1 
C) electromagnetic radiation with a frequency of 105 s-1 
D) electromagnetic radiation with a wavelength of 10 cm 
E) electromagnetic radiation with a wavenumber of 106 cm-1

Question 18

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

Accepted Answer

A) CH3CH2CH2CO2H 
B) CH3CH2CH2CN 
C) CH3CH2CH2CH2OH 
D) CH3CH2CH2CONH2 
A) CH3CH2CH2CO2H 
B) CH3CH2CH2CN 
C) CH3CH2CH2CH2OH 
D) CH3CH2CH2CONH2

Question 19

Give the m/z ratio that corresponds to the molecular ion in the mass spectrum of 2-bromobutane.

Accepted Answer

The answer of Give the m/z ratio that corresponds to...

Question 20

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

Accepted Answer

A) CH3CH2OCH2CH3 
B) CH3CO2CH3 
C) CH3CH2CCH 
D) CH3CH2SCH3 
A) CH3CH2OCH2CH3 
B) CH3CO2CH3 
C) CH3CH2CCH 
D) CH3CH2SCH3

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

When a solution of an organic compound absorbs light whose wavelength is 700 nm,the solution appears

What does "m/z" stand for and what does it mean?

Deduce a possible structure for the compound with the IR absorptions below. C4H8O: 3000,2800,2715,1715 cm-1

Which compound's mass spectrum shows peaks at M,M+2,and M+4 whose abundances are in a ratio of 1:2:1?

How could IR spectroscopy be used to distinguish between the following pair of compounds? (CH3)3N and CH3NHCH2CH3

How could you distinguish the mass spectrum of 2,2-dimethylpropane from that of isopentane?

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

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

A compound shows a molecular ion peak at m/z 167.The relative intensities of the M and M+1 peaks are 50.0 and 4.4 respectively.How many carbons are in each molecule of the compound?

How could IR spectroscopy be used to distinguish between the following pair of compounds? HOCH2CH2CHO and CH3CH2CO2H

Which compound has the lowest carbonyl absorption frequency in an infrared spectrum?

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

Which of the following m/z values correspond to the molecular ion peak of the following compound?

Absorption of UV-visible energy by a molecule results in

Which of the following increases the absorbance of a solution of phenol in ethanol?

When a solution of an organic compound absorbs light whose wavelength is 400 nm,the solution appears

Which of the following is highest in energy per photon?

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

Give the m/z ratio that corresponds to the molecular ion in the mass spectrum of 2-bromobutane.

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

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

Deduce a possible structure for the compound with the IR absorptions below. C₄H₈O: 3000,2800,2715,1715 cm^-1

How could IR spectroscopy be used to distinguish between the following pair of compounds? (CH₃)₃N and CH₃NHCH₂CH₃

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

How could IR spectroscopy be used to distinguish between the following pair of compounds? HOCH₂CH₂CHO and CH₃CH₂CO₂H

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

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

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