Deck 13: Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Question 1

A normal alkane with three carbon atoms is called ________

A) pentane.
B) butane.
C) methane.
D) ethane.
E) propane.

Answer 1

propane.

Question 2

A sample, 0.123 moles of an unknown compound containing only carbon and hydrogen, was found to fully react with 0.123 moles of hydrogen gas. Based on this data, we know that the unknown compound must be ________

A) an alkane.
B) an alkene.
C) an alkyne.
D) either an alkane or an alkene.
E) either an alkene or an alkyne.

Answer 2

an alkene.

Question 3

Which of the following structures is an unsaturated hydrocarbon?

A)
B)
C)
D)

Answer 3

Question 4

The spatial arrangement at each carbon atom in an alkane is ________, and the hybridization is ________.

A) linear; sp
B) linear; sp³
C) trigonal planar; sp²
D) tetrahedral; sp³
E) trigonal planar; sp³

Question 5

A normal alkane with seven carbon atoms is called ________

A) decane.
B) heptane.
C) nonane.
D) hexane.
E) octane.

Question 6

Which structure contains the alkyne functional group?

A)
B)
C)
D)
E)

Question 7

Which structure contains the ester functional group?

A)
B)
C)
D)
E)

Question 8

Organic chemistry encompasses the chemistry of all ________

A) hydrocarbons.
B) functional groups.
C) monomers, oligomers, and polymers.
D) naturally occurring compounds.
E) carbon compounds.

Question 9

A saturated compound composed solely of carbon and hydrogen must be ________

A) an alkane.
B) an alkene.
C) an alkyne.
D) either an alkane or an alkene.
E) either an alkene or an alkyne.

Question 10

Which of the following tends to be true of polymers but not small molecules?
I.Variable instead of constant composition
II.A poorly defined melting point
III.Solid state regions that are disordered

A) I
B) II
C) III
D) I, II, and III
E) None of these, as polymers are molecules just like small molecules only bigger.

Question 11

Which one of the following statements is true about normal alkanes?

A) They all exhibit strong hydrogen bonding with one another and with water.
B) They all contain carbon, hydrogen, and oxygen in consistent ratios.
C) Some are gases, some are liquids, and some are solids at room temperature.
D) Some are yellow, some are red, and some are blue, depending on the chain length.
E) They have the formula C_nH_2n+2 if they are linear or branched or C_nH_2n if they are cyclic.

Question 12

A sample, 0.123 moles of an unknown compound containing only carbon and hydrogen, was found to fully react with 0.246 moles of hydrogen gas. Based on this data, we know that the unknown compound must be ________

A) an alkane.
B) an alkene.
C) an alkyne.
D) either an alkane or an alkene.
E) either an alkene or an alkyne.

Question 13

A compound composed solely of carbon and hydrogen that is unsaturated must be ________

A) an alkane.
B) an alkene.
C) an alkyne.
D) either an alkane or an alkene.
E) either an alkene or an alkyne.

Question 14

The basic building block of a polymer is called ________

A) a functional group.
B) a monomer.
C) a monotone.
D) an oligomer.
E) an addition.

Question 15

Which structure contains the ketone functional group?

A)
B)
C)
D)
E)

Question 16

A subunit of an organic compound that confers particular chemical and physical properties is termed ________

A) a monomer.
B) an oligomer.
C) a functional group.
D) a synthetic unit.
E) an isomer.

Question 17

Which is not true about n-alkanes?

A) Their formulas are all C_nH_2n+2.
B) All of the carbon atoms are centers of tetrahedral geometry.
C) Their melting points increase with the number of carbon atoms.
D) Their vapor pressures increase with the number of carbon atoms.
E) All of the carbons are sp³ hybridized.

Question 18

When 1.0 mol of an alkene with one degree of unsaturation is hydrogenated, how many moles of hydrogen gas react?

A) 0 mol
B) 1.5 mol
C) 0.5 mol
D) 1.0 mol
E) 2.0 mol

Question 19

What is the degree of unsaturation of CH₂ CH -C
CH?

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

Question 20

A hydrocarbon is a compound that contains ________

A) carbon with hydrogen and oxygen in the ratio 2:1.
B) carbon with hydrogen and oxygen in any ratio.
C) only carbon and hydrogen.
D) carbon, hydrogen, and any functional groups.
E) carbon and any other elements.

Question 21

Most simple ionic compounds that are soluble in water are not soluble in organic solvents. However, replacing a common cation such as Na⁺ with an alkyl ammonium ion with four alkyl groups greatly enhances solubility of the ionic compound in many organic solvents. Which formula represents the tetrabutylammonium ion that is found in tetrabutylammonium bromide?

A) [(CH₃)₄N]⁺
B) [(CH₃CH₂)₄N]⁺
C) [(CH₃(CH₂)₂)₄N]⁺
D) [(CH₃(CH₂)₃)₄N]⁺
E) [C(CH₃)₃NH₂]⁺

Question 22

Which of these molecules are structural isomers of n-octane (C₈H₁₈)?

A) I, III, and IV
B) II and V
C) only II has 8 carbon atoms in a chain
D) III and IV
E) I, II, III, IV, and V

Question 23

Isooctane has the following structure. In this structure, how many carbon atoms are bonded to three other carbon atoms?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 24

Cyclic alkanes differ from normal alkanes in ________

A) the ratio of hydrogen to carbon.
B) their utility as a combustible fuel.
C) the orbital hybridization on the carbon atoms.
D) the number of hydrogens bonded to nonterminal carbon atoms.
E) the degree to which electrons are delocalized.

Question 25

What is the systematic name of the molecule shown below?

A) 2,2,3,4-tetramethylpentane
B) 2,3,4,4-tetramethylpentane
C) 1,2,3,4,4-pentamethylbutane
D) 1,1,1,2,3,3-hexamethylpropane
E) 2-tert-butyl-3-methylbutane

Question 26

What is the molecular formula for the following compound?

A) C₆H₁₁
B) C₆H₁₂
C) C₇H₁₁
D) C₇H₁₂
E) C₇H₁₄

Question 27

Identify the molecules that are structural isomers of each other.

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

Question 28

What is the molecular formula for the compound illustrated below?

A) C₅H₈
B) C₅H₉
C) C₅H₁₀
D) C₅H₁₁
E) C₅H₁₂

Question 29

Which of the following is/are true regarding cyclohexane, whose carbon skeleton is shown? I. The molecule is flat.
II) Each carbon is bonded to four other atoms.
III) Each carbon is sp³ hybridized.

A) I only
B) II only
C) III only
D) II and III only
E) I, II, and III

Question 30

Which statement best describes how these three molecules are related?

A) They are not related, they are different molecules.
B) They are structural isomers.
C) They are stereoisomers.
D) They illustrate cis-trans isomerization.
E) They are the same compound.

Question 31

The C-C-C bond angles in octane (CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₃) are ________

A) 180°.
B) 120°.
C) 90°.
D) 109.5°.
E) 60°.

Question 32

A molecule with the formula C₇H₁₄ was found to have carbons that were all identical in terms of structure. That is, each carbon atom was bonded to exactly the same kinds of atoms as all the rest. What is a reasonable structure for this molecule?

A) CH₃(CH₂)₅CH₃
B)
C) CH₂(CH₂)₅CH₂
D)

Question 33

Name the compound with the structural formula CH₃(CH₂)₁₆CH₃.

A) n-octane
B) n-hexadecane
C) n-octadecane
D) n-decane
E) 1,16-dimethylhexadecane

Question 34

What is the molecular formula for the compound illustrated below?

A) C₅H₇
B) C₅H₈
C) C₅H₉
D) C₅H₁₀
E) C₅H₅

Question 35

Which of the following pairs has the same molecular formula?

A) hexene and cyclohexane
B) octane and cyclooctane
C) hexane and benzene
D) hexane and cyclohexene
E) methyl and methylene

Question 36

The -CH₂- unit is known as ________

A) a methyl group.
B) a methylene group.
C) an acetylene group.
D) an alkyne group.
E) an alkene group.

Question 37

Which of the following is a methyl group?

A) -CH₂
B) =CH₂
C) -CH₂-
D) =CH=
E) -CH₃

Question 38

What is the formula for n-nonane?

A) CH₃(CH₂)₉CH₃
B) CH₃(CH₂)₇CH₃
C) CH₃(CH₂)₁₇CH₃
D) CH₃(CH₂)₅CH₃
E) CH₃(CH₂)₈CH₃

Question 39

What is the molecular formula for the following compound?

A) C₄H₅O₂
B) C₄H₆O₂
C) C₄H₇O₂
D) C₄H₈O₂
E) C₄H₁₀O₂

Question 40

Without working out all the structures, which has the larger number of structural isomers, C₁₄H₃₀ or C₁₅H₃₂?

A) C₁₄H₃₀
B) C₁₅H₃₂
C) They have the same number of isomers.
D) There is no way to tell without working out all the structures.

Question 41

Name the compound.

A) 1-butene
B) 1-butyne
C) 2-butene
D) 2-butyne
E) butane

Question 42

Name the compound.

A) cis-3-octene
B) trans-3-octene
C) cis-5-octene
D) trans-5-octene
E) 1-ethyl-2-butyl ethylene

Question 43

Where is the carbon-carbon double bond in the hydrocarbon shown? The numbers refer to
The C-C bonds from left to right.

A) on the left, 1
B) in the middle, 2
C) on the right, 3
D) on each bond
E) spread over all three bonds because of resonance

Question 44

The general formula for an alkane is ________

A) C_nH_2n.
B) C_nH_n.
C) C_nH_2n+2.
D) C_nH_2n+4.
E) C_nH_2n-2.

Question 45

Which of the following shows a small section of polyethylene?

A)
B)
C)
D)
E)

Question 46

How many structural isomers (also called constitutional isomers) are there for propylene, and why?

A) two, because of resonance
B) two, because of geometrical isomerism
C) two, because the double bond can be in either one of two locations
D) none, because the two skeletal structures can be superimposed
E) none, because double bonds always occur on the right in alkenes

Question 47

Name the compound.

A) 3-methyl-6-heptene
B) 5-ethyl-1-hexene
C) 5-methyl-1-heptene
D) 2-ethyl-5-hexene
E) 3-methylpentylethylene

Question 48

A homopolymer is a polymer in which ________

A) each polymer has the same mass.
B) each polymer has the same mass and structure.
C) the monomers are distributed uniformly throughout the polymer.
D) the polymers are distributed uniformly throughout the solution.
E) there is only one monomer unit.

Question 49

Does this molecule have both cis and trans isomers?

A) Yes, this is the cis isomer.
B) Yes, this is the trans isomer.
C) No, it has only the cis isomer.
D) No, it has only the trans isomer.
E) No, this molecule does not have cis-trans isomerism.

Question 50

Which of the following structures represents cyclohexene?

A)
B)
C)
D)

Question 51

Which of the following is not likely to be a component of a natural gas deposit?

A) CH₄
B) C₃H₈
C) C₄H₈
D) C₄H₁₀
E) C₈H₁₈

Question 52

For each of the bonds in the figure below, identify whether the bond is cis, trans, or neither cis nor trans.

A) I-cis; II-trans; III-cis
B) I-trans; II-cis; III-trans
C) I-neither; II-trans; III-cis
D) I-neither; II-cis; III-trans
E) I-neither; II-cis; III-cis

Question 53

Consider the 1,2-dichloro derivative of ethylene, in which one of the hydrogen atoms on each of the carbon atoms in ethylene is substituted with a chlorine atom, giving the structural formula CHClCHCl. Does this molecule have geometrical isomers? Remember that ethylene does not.

A) Yes, because the chlorines can be placed on the same or opposite sides of the double bond.
B) Yes, because the chlorines can be placed on either one or both of the carbons.
C) No, because both the formula and bonds are the same in all skeletal structures.
D) No, because the two structures can interconvert through bond rotation.
E) No, because there are less than four atoms bound to each carbon.

Question 54

An alkyne is characterized by a ________ bond between carbon atoms that have a ________ local molecular geometry and ________ hybridization.

A) single; linear; sp
B) single; linear; sp³
C) double; trigonal planar; sp²
D) double; tetrahedral; sp³
E) triple; linear; sp

Question 55

An alkyne is characterized by a ________ bond between carbon atoms that have a ________ local molecular geometry and ________ hybridization.

A) single; linear; sp
B) single; linear; sp³
C) double; trigonal planar; sp²
D) double; tetrahedral; sp³
E) triple; linear; sp

Question 56

Consider the 1,2-dichloro derivative of ethylene, in which one of the hydrogen atoms on each of the carbon atoms in ethylene is substituted with a chlorine atom, giving the condensed structure CHClCHCl. Which of the following is true?

A) The cis isomer is more polar.
B) The trans isomer is more polar.
C) Neither cis nor trans isomers are polar.
D) Both cis and trans isomers are equally polar.
E) There are no isomers for this molecule.

Question 57

Name the compound.

A) trans-3-hexene
B) cis-3-hexene
C) trans-4-hexene
D) cis-4-hexene
E) 1,2-diethylethylene

Question 58

Crude oil is composed mostly of

A) liquefied carbon.
B) liquefied rock and soil.
C) compounds containing carbon and hydrogen.
D) decomposed anaerobic bacteria.
E) compounds containing carbon, hydrogen, oxygen, and nitrogen.

Question 59

Which of the following monomers is used in making the polymer illustrated below?

A)
B)
C)
D)
E)

Question 60

Which one of the following best describes this molecule?

A) dodecane
B) cyclohexane (boat conformation)
C) cyclohexane (chair conformation)
D) puckerane
E) trans-cyclohexane

Question 61

Gasoline additives such as ethanol are employed to ________

A) decrease odor.
B) promote complete combustion.
C) decrease octane rating.
D) make the fuel less volatile.
E) increase fuel value.

Question 62

Are the methyl groups in xylene included in the aromatic part of the molecular structure?

A) Yes, the aromatic bonding extends throughout the molecule.
B) Yes, but only when the resonance form with double bonds to the methyl groups exists.
C) No, only the carbons in the ring are involved in aromatic bonding.
D) No, only the hydrogens in the ring are involved in aromatic bonding.
E) No, only the carbon atoms in xylene are involved in aromatic bonding, not the hydrogens.

Question 63

Which of the following is an amine functional group?

A) -COOH
B) -OH
C) -NH
D) -NH₂
E) -CONH₂

Question 64

How many structural isomers does xylene have? Xylene is a benzene ring with two methyl groups attached to it.

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

Question 65

Do carbon atoms in aromatic hydrocarbon molecules (not ions) obey the octet rule?

A) No, each carbon is bonded to only three atoms, and there are no lone pairs.
B) No, each carbon has one single bond and one double bond for a total of only six electrons.
C) Yes, each carbon obeys the octet rule.
D) Yes, but only because the double bond is counted twice owing to the resonance structures.
E) Yes, but only when one or the other resonance form dominates, not when the structure is an average of the two.

Question 66

Which of the following class of compounds is not used in gasoline?

A) alcohols
B) ethers
C) thiols
D) alkanes
E) octanes

Question 67

What type of amine is adrenaline, which is depicted below?

A) aromatic
B) auxiliary
C) primary
D) secondary
E) tertiary

Question 68

How many structural isomers does toluene (C₆H₅CH₃) have?

A) 0
B) 2
C) 3
D) 4
E) 5

Question 69

Delocalized bonding in aromatic hydrocarbons is possible because of ________

A) the fact that electrons can move very quickly from one resonance form to another.
B) adjacent 2p_z orbitals each having one electron.
C) Wade's rules.
D) double-headed arrows.
E) Cooper pairs.

Question 70

Which of the following is not a difference between cyclohexane and benzene?

A) Cyclohexane is puckered, but benzene is planar.
B) Cyclohexane carbons are sp³ hybridized, but benzene carbons are sp² hybridized.
C) Cyclohexane is a combustible hydrocarbon, but benzene has such a stable aromatic structure that it does not burn.
D) Cyclohexane has 12 hydrogen atoms in its structure, but benzene has 6 hydrogen atoms in its structure.
E) Cyclohexane is not aromatic, but benzene is.

Question 71

What functional group is found in the following molecule?

A) amine
B) amide
C) ammonia
D) ammonium
E) amonyl

Question 72

Which statement about alkanes, alkenes, and alkynes is not correct?

A) Alkanes are much less reactive than alkenes and alkynes.
B) The melting and boiling points increase as the number of carbon atoms in a normal alkane increases.
C) When they have the same number of carbon atoms, branched alkanes have lower melting and boiling points than normal alkanes.
D) Alkenes and alkynes, but not alkanes, undergo addition reactions.
E) Cis and trans stereoisomers occur in both alkenes and alkynes.

Question 73

The characteristic "fishy" odor comes from methylamine (CH₃NH₂), which is similar to ammonia (NH₃) in structure and also in its ability to react with acids as a weak base. Why would the acid form of methylamine not have as strong an odor as methylamine?

A) because it would decompose to methane and ammonia
B) because it would not be volatile as a polyatomic ion
C) because it would melt in the acid
D) because it would decompose to carbon, hydrogen, and nitrogen
E) because it would have a different three-dimensional structure

Question 74

What is another name for methylbenzene?

A) toluene
B) xylene
C) naphthalene
D) Jolene
E) 1-methyl-2,4,6-cyclohexene

Question 75

The alcohol functional group has the bonding arrangement ________

A) C__O__H.
B) C__O__C.
C) Al __O__0H.
D) C__O__O__H.
E) R__O__H, where R is any element.

Question 76

Naphthalene, a polyaromatic hydrocarbon, is used for mothballs. Its molecular formula is C₁₀H₈. How many fused aromatic rings does naphthalene have in its molecular structure?

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

Question 77

The monomer for polystyrene is shown below. Which of the bonds is involved in the polymerization process?

A) I only
B) II only
C) III only
D) IV only
E) Bonds I-IV are all involved in polymerization.

Question 78

Which statement about alkanes, alkenes, and alkynes is not correct?

A) Alkanes are much less reactive than alkenes and alkynes.
B) The melting and boiling points increase as the number of carbon atoms in a normal alkane increases.
C) When they have the same number of carbon atoms, branched alkanes have higher melting and boiling points than normal alkanes.
D) Alkenes and alkynes, but not alkanes, undergo addition reactions.
E) Cis and trans stereoisomers occur only in alkenes.

Question 79

The Aldrich Chemical Company catalogue lists the three isomers of xylene as having boiling points of 143-145°C, 138-139°C, and 138°C. Which isomer has the highest boiling point, and why?

A) o-xylene (1,2-dimethylbenzene) because of its polarity
B) p-xylene (1,4-dimethylbenzene) because of its polarity
C) p-xylene (1,4-dimethylbenzene) because of its para-normalcy
D) m-xylene (1,3-dimethylbenzene) because of its C₂ symmetry
E) o,m,p-xylene (1,2,3,4-tetramethylbenzene) because of its molar mass

Question 80

Which of the following is/are true regarding aromatic hydrocarbons?
I.They are particularly stable because of delocalized bonding.
II.They are particularly stable because of their covalent network bonding.
III.They are particularly unstable as evidenced by their tendency to evaporate.

A) I only
B) II only
C) III only
D) I and II only
E) I and III only