Question 1

How many noncyclic isomers including geometric isomers of C4H8 exist?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5 D

Question 2

In the rings of heterocyclic compounds we can find one or more atoms that are not carbon atoms

Accepted Answer

A) True 
 B)False  True

Question 3

Which of the following chiral compounds is(are) R enantiomer(s)?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  II + III 
E)  I + II 
A)  I 
B)  II 
C)  III 
D)  II + III 
E)  I + II C

Question 4

Give the condensed structural formula for 3-bromopentane.

Accepted Answer

A)  CH3CH2CHBrCH2CH2CH3 
B)  CH3CHBrCH2CH2CH3 
C)  (CH3)3CHBrCH2CH3 
D)  CH3CH2CHBrCH2CH3 
E)  CH3CH2CBr3CH2CH3 
A)  CH3CH2CHBrCH2CH2CH3 
B)  CH3CHBrCH2CH2CH3 
C)  (CH3)3CHBrCH2CH3 
D)  CH3CH2CHBrCH2CH3 
E)  CH3CH2CBr3CH2CH3

Question 5

Choose the INCORRECT statement.

Accepted Answer

A)  In thermal cracking large hydrocarbon molecules are broken down into smaller molecules, ideally, molecules in the gasoline range. 
B)  Reforming converts straight-chain hydrocarbons into branched-chain hydrocarbons. 
C)  Branched-chain hydrocarbons have higher octane numbers. 
D)  Alkylation is the joining of small hydrocarbon fragments to larger molecules. 
E)  Engine knocking is caused by the smooth firing of gasoline. 
A)  In thermal cracking large hydrocarbon molecules are broken down into smaller molecules, ideally, molecules in the gasoline range. 
B)  Reforming converts straight-chain hydrocarbons into branched-chain hydrocarbons. 
C)  Branched-chain hydrocarbons have higher octane numbers. 
D)  Alkylation is the joining of small hydrocarbon fragments to larger molecules. 
E)  Engine knocking is caused by the smooth firing of gasoline.

Question 6

Why does benzene have a much higher boiling point (80°C) than hexane (69°C), even though they have the same number of carbons?

Accepted Answer

A)  Benzene has fewer hydrogens than hexane. 
B)  Benzene is much more polar than hexane which enhances the attractive forces between molecules and raises the boiling point. 
C)  Benzene is planar and has delocalized electron density which increases the attractive forces between molecules and raises the boiling point. 
D)  Hexane has more Kekulé structures than benzene. 
E)  Benzene can covalently bond to another benzene molecule which increases its boiling point. 
A)  Benzene has fewer hydrogens than hexane. 
B)  Benzene is much more polar than hexane which enhances the attractive forces between molecules and raises the boiling point. 
C)  Benzene is planar and has delocalized electron density which increases the attractive forces between molecules and raises the boiling point. 
D)  Hexane has more Kekulé structures than benzene. 
E)  Benzene can covalently bond to another benzene molecule which increases its boiling point.

Question 7

Which two simple functional groups make carboxyl group?

Accepted Answer

A)  Aldehyde and keto groups 
B)  Aldehyde and hydroxyl groups 
C)  Keto and hydroxyl groups 
D)  Ester and hydroxyl groups 
E)  Ester and ether groups 
A)  Aldehyde and keto groups 
B)  Aldehyde and hydroxyl groups 
C)  Keto and hydroxyl groups 
D)  Ester and hydroxyl groups 
E)  Ester and ether groups

Question 8

How many primary, secondary, tertiary and quaternary carbon atoms are there in the structure of 2,4,6-trimetylheptane?

Accepted Answer

A)  5 primary, 2 secondary, 2 tertiary and 1 quaternary carbon atoms 
B)  5 primary, 3 secondary, 2 tertiary and 0 quaternary carbon atoms 
C)  4 primary, 4 secondary, 2 tertiary and 0 quaternary carbon atoms 
D)  4 primary, 2 secondary, 2 tertiary and 2 quaternary carbon atoms 
E)  5 primary, 2 secondary, 3 tertiary and 0 quaternary carbon atoms 
A)  5 primary, 2 secondary, 2 tertiary and 1 quaternary carbon atoms 
B)  5 primary, 3 secondary, 2 tertiary and 0 quaternary carbon atoms 
C)  4 primary, 4 secondary, 2 tertiary and 0 quaternary carbon atoms 
D)  4 primary, 2 secondary, 2 tertiary and 2 quaternary carbon atoms 
E)  5 primary, 2 secondary, 3 tertiary and 0 quaternary carbon atoms

Question 9

If an ethyl group is substituted for one hydrogen of cyclohexane, what would be the preferred position of that ethyl substituent on the ring?

Accepted Answer

A)  axial position 
B)  equatorial position 
C)  chair position 
D)  boat position 
E)  twist boat conformation 
A)  axial position 
B)  equatorial position 
C)  chair position 
D)  boat position 
E)  twist boat conformation

Question 10

Give the condensed structural formula for propanone.

Accepted Answer

A)  CH3COCH3 
B)  CH3CH2CHO 
C)  CH3OCH2CH3 
D)  CH3OCH3 
E)  CH3CH2CO 
A)  CH3COCH3 
B)  CH3CH2CHO 
C)  CH3OCH2CH3 
D)  CH3OCH3 
E)  CH3CH2CO

Question 11

The diol, ethylene glycol, is used extensively as an antifreeze additive in automobile radiators. What properties of ethylene glycol make it a good antifreeze?

Accepted Answer

A)  Ethylene glycol coats the radiator to prevent crystallization of ice at low temperatures. 
B)  Ethylene glycol has a higher boiling point than water and is soluble in water. 
C)  Ethylene glycol has a lower boiling point than water and is soluble in water. 
D)  Ethylene glycol forms a film on the surface of the water to prevent ice formation in the radiator. 
E)  Ethylene glycol will remain in the radiator after the water evaporates. This prevents freezing in cold climates. 
A)  Ethylene glycol coats the radiator to prevent crystallization of ice at low temperatures. 
B)  Ethylene glycol has a higher boiling point than water and is soluble in water. 
C)  Ethylene glycol has a lower boiling point than water and is soluble in water. 
D)  Ethylene glycol forms a film on the surface of the water to prevent ice formation in the radiator. 
E)  Ethylene glycol will remain in the radiator after the water evaporates. This prevents freezing in cold climates.

Question 12

Which of the following structures represent the structure of trans-1-bromo-2-methylcyclohexane?

Accepted Answer

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

Question 13

Which statements regarding chiral compounds are correct? 
I. "Chiral carbon" is synonymous with "asymmetric carbon".
II. The presence of one chiral carbon in a structure results in two possible enantiomers.
III. Two enantiomers can be interconverted without breaking any bonds.
IV. Two chiral molecules are mirror images of each other.
V. Two chiral molecules have significantly different chemical properties.

Accepted Answer

A)  II), III), and V) 
B)  I), II), and IV) 
C)  I), III), and IV) 
D)  II), IV) and V) 
E)  III), and V) 
A)  II), III), and V) 
B)  I), II), and IV) 
C)  I), III), and IV) 
D)  II), IV) and V) 
E)  III), and V)

Question 14

C3H8O has how many skeletal isomers?

Accepted Answer

A)  2 
B)  4 
C)  5 
D)  6 
E)  3 
A)  2 
B)  4 
C)  5 
D)  6 
E)  3

Question 15

Choose the INCORRECT statement.

Accepted Answer

A)  Axial H atoms are directed above and below the cyclohexane ring. 
B)  A substitution reaction typically involves a functional group replacing a hydrogen atom on a chain or ring containing molecule. 
C)  A free radical is a compound with an unpaired electron. 
D)  LPG is linear polymerized gas. 
E)  Unsaturated usually means a double, triple or delocalized electron system is present in the molecule. 
A)  Axial H atoms are directed above and below the cyclohexane ring. 
B)  A substitution reaction typically involves a functional group replacing a hydrogen atom on a chain or ring containing molecule. 
C)  A free radical is a compound with an unpaired electron. 
D)  LPG is linear polymerized gas. 
E)  Unsaturated usually means a double, triple or delocalized electron system is present in the molecule.

Question 16

To produce an organic ester, one uses a carboxylic acid and a(n) ________.

Accepted Answer

A)  alkyl halide 
B)  alkane 
C)  alcohol 
D)  aldehyde 
E)  ketone 
A)  alkyl halide 
B)  alkane 
C)  alcohol 
D)  aldehyde 
E)  ketone

Question 17

When determining the priority of substituents is "A substituent atom of higher atomic number has higher priority over a substituent atom with lower atomic number."

Accepted Answer

A) True 
 B)False

Question 18

Which of the following structures represents a structure of R isomer of 1-amino-2-propanol?

Accepted Answer

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

Question 19

Combustion of 493 mg of a hydrocarbon gave 1549 mg CO2 and 633.9 mg H2O. What is the molecular formula if the molecular weight is subsequently found to be 42?

Accepted Answer

A)  CO2 
B)  CH2 
C)  C6H12 
D)  C2H2O 
E)  C3H6 
A)  CO2 
B)  CH2 
C)  C6H12 
D)  C2H2O 
E)  C3H6

Question 20

Which of the following synthetic procedures are plausible? 
I. synthesis of esters from alcohols and acids
II. synthesis of ethers from acids and alcohols
III. synthesis of amides from acids and amines
IV. synthesis of alcohols from alkanes and water
V. synthesis of aldehydes from alcohols and oxidizing agents

Accepted Answer

A)  I), III), and IV) 
B)  I), III), and V) 
C)  II), III), and V) 
D)  II), III), and IV) 
E)  III), IV), and V) 
A)  I), III), and IV) 
B)  I), III), and V) 
C)  II), III), and V) 
D)  II), III), and IV) 
E)  III), IV), and V)

Exam 26: Structures of Organic Compounds

How many noncyclic isomers including geometric isomers of C4H8 exist?

In the rings of heterocyclic compounds we can find one or more atoms that are not carbon atoms

Which of the following chiral compounds is(are) R enantiomer(s)?

Give the condensed structural formula for 3-bromopentane.

Choose the INCORRECT statement.

Why does benzene have a much higher boiling point (80°C) than hexane (69°C), even though they have the same number of carbons?

Which two simple functional groups make carboxyl group?

How many primary, secondary, tertiary and quaternary carbon atoms are there in the structure of 2,4,6-trimetylheptane?

If an ethyl group is substituted for one hydrogen of cyclohexane, what would be the preferred position of that ethyl substituent on the ring?

Give the condensed structural formula for propanone.

The diol, ethylene glycol, is used extensively as an antifreeze additive in automobile radiators. What properties of ethylene glycol make it a good antifreeze?

Which of the following structures represent the structure of trans-1-bromo-2-methylcyclohexane?

C3H8O has how many skeletal isomers?

Choose the INCORRECT statement.

To produce an organic ester, one uses a carboxylic acid and a(n) ________.

When determining the priority of substituents is "A substituent atom of higher atomic number has higher priority over a substituent atom with lower atomic number."

Which of the following structures represents a structure of R isomer of 1-amino-2-propanol?

Combustion of 493 mg of a hydrocarbon gave 1549 mg CO2 and 633.9 mg H2O. What is the molecular formula if the molecular weight is subsequently found to be 42?

Matter - Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Additional Aspects

Intermolecular Forces: Liquids and Solids

Solutions and Their Physical Properties

Chemical Kinetics

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acid-Base Equilibria

Solubility and Complex-Ion Equilibria

Spontaneous Change: Entropy and Free Energy

Electrochemistry

Main Group Elements I: Groups 1, 2, 13, and 14

Main Group Elements II: Groups 18, 17, 16, 15, and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry 1-41

Reactions of Organic Compounds

Chemistry of the Living State

Filters

How many noncyclic isomers including geometric isomers of C₄H₈ exist?

C₃H₈O has how many skeletal isomers?

Combustion of 493 mg of a hydrocarbon gave 1549 mg CO₂ and 633.9 mg H₂O. What is the molecular formula if the molecular weight is subsequently found to be 42?