Organic Chemistry Hydrocarbons Full Test Bank Chapter 6

Test questions for Chapter 6

Organic Chemistry: Hydrocarbons

1. Which of the following statements describes why “good fats” are considered good and “bad fats” are considered bad?
   1. A diet high in saturated fat can result in heart disease.
   2. A diet high in unsaturated fat can result in type 2 diabetes.
   3. A diet high is trans fats can result in a decreased risk of cancer.
   4. A diet high in unsaturated fats can result in a decreased risk of cancer

a. All of these statements are true.

b. I and II are true.

c. I, III, and IV are true.

d. I and IV are true.

e. II and III are true.

1. Which of the following foods should be avoided in order to limit the consumption of saturated fat?
   • 1. whole milk
     2. cheese
     3. ice cream
     4. red meat
     5. All of the above
2. Which of these fatty acids is an oil at room temperature?

• • 1. A only
    2. B only
    3. A and B
    4. A, D and E
    5. C and B

1. Which of these fatty acids is considered a “good fat”?

• 1. None because all fats are bad
  2. All of them because all fats taste good
  3. B and E because the higher the molecular weight, the better the fat is
  4. C and B because these molecules contain cis double bonds
  5. A, D, and E because these molecules do not contain any double bonds

1. Which of the fatty acids are saturated?

1. All of them are saturated.
2. Only B and C are saturated.
3. Only A, D, and E are saturated.
4. A, D, B, and E are saturated.
5. None of them are saturated.
6. Why do saturated fats have higher melting points than unsaturated fats?
   • 1. Saturated fats stack better than unsaturated fats and therefore have more dispersion forces between them.
     2. Saturated fats stack better than unsaturated fats and therefore have fewer dispersion forces between them.
     3. Unsaturated fats stack better than saturated fats and therefore have more dispersion forces between them.
     4. Unsaturated fats stack better than saturated fats and therefore have fewer dispersion forces between them.
     5. Actually, saturated fats have lower melting points than unsaturated fats.
7. Organic chemistry is the study of compounds that
8. are biologically important.
9. contain oxygen.
10. make up living things.
11. are not harmful to the environment.
12. contain carbon.
13. Which of the following elements is NOT a heteroatom?
14. carbon
15. sulfur
16. nitrogen
17. oxygen
18. phosphorous
19. Which of the following compounds contains a heteroatom?

I II III IV

1. All of these compounds contain a heteroatom.
2. I and II contain a heteroatom.
3. III and IV contain a heteroatom.
4. Only III contains a heteroatom.
5. I, II, and III contain a heteroatom.
6. Which of the following compounds is inorganic?
7. CH₄O
8. CH₄
9. CO₂
10. NH₃
11. CH₂O
12. A hydrocarbon contains
13. only carbon, hydrogen, nitrogen and oxygen.
14. only carbon and hydrogen.
15. only carbon, hydrogen, and oxygen.
16. only carbon, hydrogen, and nitrogen.
17. any element except carbon and hydrogen.
18. Which of the following compounds is a valid Lewis structure of a hydrocarbon?

I II III IV

1. All of these compounds are valid structures of hydrocarbons.
2. I, II, and IV are valid structures of hydrocarbons.
3. III and IV are valid structures of hydrocarbons.
4. Only III is a valid structure of hydrocarbons.
5. Only IV is a valid structure of hydrocarbons.
6. Which of the following compounds is a saturated hydrocarbon?

I II III IV

1. I only
2. I and II
3. IV only
4. III and IV
5. All of these are saturated hydrocarbons.
6. An alkene has _______ a saturated hydrocarbon with the same number of hydrogens.
7. two more hydrogens than
8. one more hydrogen than
9. the same number of hydrogens as
10. one fewer hydrogen than
11. two fewer hydrogens than
12. A compound with the molecular formula C_nH_2n+2 is called a(n)______or a ______.
13. alkane, saturated hydrocarbon
14. alkane, unsaturated hydrocarbon
15. alkene, saturated hydrocarbon

d. alkene, unsaturated hydrocarbon

e. alkene, alkyne

1. Which of the hydrocarbons listed are unsaturated?
2. alkane
3. alkene
4. alkyne
5. aromatic
6. alkanes only
7. alkenes and alkynes only
8. alkenes, alkynes, and adromatics
9. alkanes, alkenes, alkynes, and aromatics
10. aromatics only
11. Which terms from this list best describe the following compound?
12. alkane
13. alkene
14. alkyne
15. aromatic
16. saturated hydrocarbon
17. unsaturated hydrocarbon

1. I and V
2. II and VI
3. III and VI
4. II and V
5. III and V
6. A molecule has the molecular formula C₅H₁₀. This molecule could be a(n) ______ and a(n) _____.
7. alkane, saturated hydrocarbon
8. alkane, unsaturated hydrocarbon
9. alkene, saturated hydrocarbon

d. alkene, unsaturated hydrocarbon.

e. alkene, alkyne.

1. Which of the following is a saturated hydrocarbon?
2. C₃H₆
3. C₆H₆
4. C₄H₆
5. C₄H₁₀
6. C₂H₄
7. Which statement best describes the solubility of hydrocarbons?
   • 1. Hydrocarbons are soluble in water and therefore hydrophobic.
     2. Hydrocarbons are insoluble in water and therefore hydrophobic.
     3. Hydrocarbons are soluble in water and therefore hydrophilic.
     4. Hydrocarbons do not dissolve in any solvent.
     5. It is not possible to generalize the solubility of hydrocarbons.
8. Which of the following structures is a branched-chain hydrocarbon?

1. I only
2. II only
3. III only
4. I and II
5. II and III
6. Which carbon is the branching carbon in the following molecule?

1. a
2. b
3. c
4. d
5. e
6. What is the IUPAC name of the following hydrocarbon?

a. propane

b. propene

c. butane

d. butane

e. pentene

1. What is the IUPAC name of the following hydrocarbon?

a. propane

b. butane

c. pentane

d. but-1-ene

e. pent-1-ene

1. Which of the following is NOT a goal of naming in the IUPAC system?
2. Each structure should have one name.
3. Each name should represent one structure.
4. It should be possible to draw a chemical structure given the name.
5. It should be possible to name any given structure.
6. The name should indicate something about the purpose of the molecule.
7. How do IUPAC names differ from the brand names of pharmaceuticals?
8. IUPAC names are systematic and brand names are not.
9. Brand names are systematic and IUPAC names are not.
10. IUPAC names are usually shorter than brand names.
11. Brand names are not used as frequently as IUPAC names.
12. IUPAC names do not follow a set of rules like brand names do.
13. Which of the following statements best describes alkanes?
    • 1. They are hydrocarbons.
      2. They contain only C-C single bonds.
      3. They take on a regular zig-zag shape.
      4. They are hydrophobic.
      5. All of the above
14. Which of the following statements about alkanes is NOT true?
15. Alkanes can move and twist.
16. Merely rotating a C-C bond does not change the identity of an alkane.
17. Alkanes are hydrophilic.
18. Alkanes more rapidly twist and rotate at higher temperatures.
19. Alkanes are often found in a zig-zag shape.
20. Which of the following structures is the best condensed structural formula for the Lewis structure given below?

1. Which skeletal line structure is the same molecule as the ball-and-stick model below?

1. Which skeletal line structure is the same molecule as the ball-and-stick model below?

1. Which of the following skeletal line structures best represents the Lewis structure below?

1. How many hydrogens are bonded to the carbons with the arrows pointing to them?

1. carbon 1: 0 carbon 2: 0
2. carbon 1: 0 carbon 2: 2
3. carbon 1: 1 carbon 2: 2
4. carbon 1: 4 carbon 2: 4
5. It is not possible to tell given the skeletal line structure.
6. Which of the following condensed structures best represents the skeletal line structure below?

1. Below is an illustration of a molecule of cyclohexane. Which of the following choices best describes why this illustration does not represent cyclohexane accurately?

1. The molecule illustrated does not contain enough carbons.
2. The molecule illustrated contains too many carbons.
3. The molecule illustrated is not saturated.
4. The molecule illustrated is flat.
5. The molecule illustrated is puckered.
6. Is the following cycloalkane more or less abundant in nature than cyclohexane?

1. more abundant because it is smaller
2. more abundant because it is more stable
3. less abundant because it is substituted
4. less abundant because the bond angles are not 109.5°
5. more abundant because it is substituted
6. What is the name of the following cycloalkane?

1. pentane
2. cyclopentane
3. butane
4. cyclobutane
5. cycloalkane
6. Which of the following skeletal line structures has the molecular formula C₅H₈?

1. Which of the following structures is nonane?

1. Which of the following structures is heptane?

1. How many hydrogens are attached to the carbons indicated below?

1. C1: 2 C2: 0
2. C1: 0 C2: 2
3. C1: 1 C2: 1
4. C1: 0 C2: 1
5. C1: 1 C2: 0
6. How many carbon atoms are in a molecule of estradiol, the steroid shown below?

1. How many hydrogen atoms are in the following structure?

1. Which of the following skeletal line structures represent the same molecule?

1. I and II
2. II and III
3. I, II, IV, and V
4. IV and V
5. II, IV, and V
6. Below is illustrated a molecule of butane. Which of the given choices is another molecule of butane in a different conformation? Assume that all atoms in each are visible.

Butane

a.

b.

c.

d.

e.

1. Which statement best describes the relationship between the following two structures?

1. They are identical.
2. They have different molecular formulas.
3. They are isomers.
4. They are conformers.
5. One is an alkene and the other is an alkyne.
6. Which statement best describes the relationship between the following two structures?

1. They are identical.
2. They have different molecular formulas.
3. They are isomers.
4. They are conformers.
5. One is an alkene and the other is an alkyne.
6. Which statement best describes the relationship between the following two structures?

1. They are identical.
2. They have different molecular formulas.
3. They are isomers.
4. They are conformers.
5. One is an alkene and the other is an alkyne.
6. Which of the molecules below are structural isomers?

I II III IV

1. I and II
2. I and IV
3. I, III, and IV
4. I and III
5. All of these are structural isomers.
6. Which structures are straight chain hydrocarbons?

I II III IV

1. I only
2. II and IV
3. II, III, and IV
4. I and III
5. All of these molecules have a straight chain.
6. Which of the molecules below are branched?

I II III IV

1. I only
2. II and IV
3. II, III, and IV
4. I and III
5. All of these molecules are branched.
6. Which of these structures below are conformers?

I II III IV

1. I and II
2. I and IV
3. I, III, and IV
4. I and III
5. All of these are conformers.
6. Are the following two molecules structural isomers?

1. No, because they do not have the same molecular formula
2. Yes, because they have the same molecular formula but different structures
3. Yes, because they have the same number of carbons
4. Yes, because they do not have the same molecular formula
5. No, because only one is branched
6. Which of the following definitions best describes structural isomers?
7. They are molecules with different structures.
8. They are molecules with the same molecular formula and the same structure.
9. They are molecules with the same physical properties.
10. They are molecules that have the same molecular formula but different structures.
11. They are molecules that look similar.
12. Which of the following skeletal line structures are isomers?

I. II. III. IV.

1. All of these are isomers.
2. I and II
3. I, II, and III
4. III and IV
5. II and III
6. What is the molecular shape around the carbon indicated with an arrow?

a. linear

b. trigonal pyramidal

c. tetrahedral

d. bent

e. trigonal planar

1. β-Carotene is the molecule that gives carrots their orange color. Which characteristic of β-carotene is primarily responsible for the orange color?

a. the branched-chain

b. the two cyclohexanes

c. the conjugated alkenes

d. the trans geometry

e. the number of carbons

1. Which of the following molecules contains a conjugated polyene?

1. What type of alkene is boxed in lovastatin, a drug used to control cholesterol levels?

• 1. A diene that is not conjugated
  2. A conjugated diene
  3. A polyene that is not conjugated
  4. A conjugated polyene
  5. This molecule does not contain an alkene.

1. Which of the following structures represents a diene?

1. Which of the following pairs of compounds are geometric isomers?

1. Which of the following pairs of molecules are geometric isomers?

1. In which of the following choices are the alkenes correctly labeled?

1. Arachidonic acid is a fat found in many foods such as meat, dairy products, and eggs. What type of carbon-carbon double bonds does arachidonic acid contain?

1. Arachidonic acid contains all trans double bonds.
2. Arachidonic acid contains all cis double bonds.
3. Arachidonic acid contains two cis and two trans double bonds.
4. Arachidonic acid contains one cis and three trans double bonds.
5. Arachidonic acid contains three cis and one trans double bonds.
6. Which pair(s) of molecules below are geometric isomers?

1. All of them
2. Pairs 2, 3, and 4
3. Pairs 1, 2, and 3
4. Pair 1, 3, and 4
5. Pair 4 only
6. Which pair(s) of molecules below are conformers?

1. Pairs 1, 3, and 4
2. Pairs 2 and 4
3. Pairs 2 and 3
4. Pair 2 only
5. Pair 4 only
6. Which pair(s) of molecules below are neither isomers nor conformers?

1. Pair 1
2. Pair 2
3. Pair 3
4. Pair 4
5. These are all either isomers or conformers.
6. Converting a cis isomer to a trans isomer
7. requires nothing. Cis and trans isomers are actually just conformers, so they interconvert all of the time.
8. requires a chemical reaction.
9. requires a physical change such as melting or boiling.
10. requires both a chemical reaction and a physical change.
11. is impossible. There is no way to convert a cis isomer to a trans isomer.
12. Ethynyl estradiol, a synthetic hormone, is a common component of birth control pills. Which bond in ethynyl estradiol is an alkyne?

1. A
2. B
3. C
4. D
5. A and C
6. A molecule has the following IUPAC name: 1-hexyne. What does this name mean?
7. The molecule is an unbranched six-carbon alkane.
8. The molecule is a branched six-carbon alkane.
9. The molecule is an unbranched six-carbon alkene.
10. The molecule is a branched six-carbon alkyne.
11. The molecule is an unbranched six-carbon alkyne.
12. What is the name of the following hydrocarbon?

1. trans-3-pentane
2. trans-3-pentene
3. cis-3-pentane
4. trans-2-pentene
5. cis-2-pentene
6. Which of the following structures is the condensed structural formula of 1-hexene?

1. Which skeletal line structure best represents 2-butyne?

1. Identify the three parts of the following IUPAC name.

1. prefix: 3-ethyl root: hexene suffix: none
2. prefix: 3-ethyl root: hex suffix: -ene
3. prefix: hex root: ene suffix: none
4. prefix: 3 root: ethyl suffix: hexene
5. prefix: eth root: yl suffix: hexene

1. When naming in the IUPAC system, the main chain has which of the following characteristics?
   • • 1. It is the part of the structure that is written horizontally.
       2. It is the longest continuous chain.
       3. It contains any double or triple bonds in the structure.
2. I, II, and III
3. I and II only
4. II and III only
5. I and III only
6. I only
7. Which of the following hydrocarbons are branched and which are straight chains?

I II III IV

• 1. All of these hydrocarbons are branched.
  2. All of these hydrocarbons are branched except II.
  3. All of these hydrocarbons are straight chains except III.
  4. I and III are branched, and II and IV are straight chains.
  5. II, III, and IV are straight chains and I is branched.

1. Which of the following condensed structures are branched and which are straight chains?

I II III

1. Branched: II Straight chain: I and III
2. Branched: I and III Straight chain: II
3. Branched: II and III Straight chain: I
4. Branched: III Straight chain: I and II
5. Branched: I and II Straight chain: III
6. What is the parent chain name of the hydrocarbon below?

1. butene
2. hexane
3. hexene
4. heptane
5. heptene
6. For naming purposes, which carbon is the double bond located in this branched-chain hydrocarbon?

1. 1
2. 2
3. 3
4. 4
5. 5
6. What are the locator number(s) and substituent name(s) for this branched-chain hydrocarbon?

1. 3-methyl
2. 2-ethyl
3. 1-ethyl-1-methyl
4. 5-ethyl
5. 5-methyl
6. What is the IUPAC name of this hydrocarbon?

1. trans-5-methyl-2-heptene
2. cis-5-ethyl-2-hexene
3. trans-3-methyl-5-heptene
4. cis-2-ethyl-5-hexene
5. trans-1-ethyl-1-methyl-2-butene
6. What is the best IUPAC name of the following branched-chain hydrocarbon?

1. trans-4-methyl-4-methyl-2-pentene
2. cis-2-methyl-2-methyl-3-pentene
3. cis-4,4-dimethyl-2-pentene
4. trans-2,2-dimethyl-3-pentene
5. cis-4,4,4-trimethyl-2-propene
6. Which of the following structure(s) is represented by the following IUPAC name?

4-ethyl-2-methylheptane

I II III IV

1. II only
2. I and II
3. I, II, and IV
4. II and III
5. All of these are 4-ethyl-2-methylheptane.
6. What is the best IUPAC name of the following branched hydrocarbon?

1. 3-methylhexene
2. 2-propyl-1-butene
3. 3-heptene
4. 2-ethyl-1-pentene
5. 4-ethyl-4-pentene
6. Which of the following structures represent benzene?

I II III IV V

• 1. II and IV
  2. I, II, and IV
  3. III and V
  4. All of them except V
  5. All of them

1. Benzene is not classified as an alkene. Why not?
2. It does not have 120° bond angles.
3. It actually contains three double bonds, not just one.
4. It is flat.
5. It is much more stable and unreactive than an alkene.
6. Actually, benzene is classified as an alkene.
7. Electrons in benzene are spread out over the six carbons in the molecule. Chemists call these electrons
8. delocalized.
9. carcinogenic.
10. highly reactive.
11. highly unstable.
12. resonance electrons.
13. The following structure is a poor representation of benzene. What is wrong with it?

1. Benzene does not have six sides.
2. Benzene is not flat.
3. Benzene is never represented with three double bonds and three single bonds.
4. Benzene does not have the molecular formula C₆H₆.
5. The bonds in benzene should all be the same length.
6. A cyclohexane molecule and a benzene molecule are illustrated below. Which of the four statements describing the relationship between benzene and cyclohexane are true?

Benzene Cyclohexane

• • 1. Benzene and cyclohexane have different molecular formulas.
    2. Benzene and cyclohexane are both flat.
    3. Benzene and cyclohexane have different C-C bond lengths.
    4. Benzene is more flexible than cyclohexane.

1. Only I is true.
2. I and III are true.
3. I, II, and III are true.
4. I and IV are true.
5. All of the statements are true.
6. What is the IUPAC name of the following molecule?

1. 3-ethyl-1-propylbenzene
2. 1-propyl-3-ethylbenzene
3. 1-ethyl-3-propylbenzene
4. 3-propyl-1-ethylbenzene
5. ethylpropybenzene
6. Aspirin contains a benzene ring substituted on the first and second carbon. Which of the following molecules is aspirin?

1. Which molecule is represented by the IUPAC name 1,4-diethylbenzene?

1. Which statement best describes the difference(s) between structures I and II in this reaction of rhodopsin in the presence of light?

Structure I Structure II

• 1. Structure II is more linear than structure I.
  2. Structure I is more linear than structure II.
  3. A cis double bond in structure I has been converted to a trans double bond in structure II.
  4. A trans double bond in structure I has been converted to a cis double bond in structure II.
     1. All of these statements are true.
     2. I and IV are true.
     3. II and IV are true.
     4. I and III are true.
     5. II and III are true.

1. What type of change is illustrated in the reaction of rhodopsin in the presence of light shown below?

Structure I Structure II

1. a physical change
2. a conformational change
3. an isomerization reaction
4. rotation about a bond as a result of free bond rotation
5. None of these are illustrated.
6. What happens in the retina as a result of the change illustrated in the reaction of rhodopsin in the presence of light?

Structure I Structure II

1. Nothing happens.
2. The retina is damaged.
3. A signal is sent to the brain that light is detected.
4. A signal is sent to the spinal cord to react to the light.
5. The retina makes more protein.