Deck 19: Organic Chemistry-Fuels, pharmaceuticals, and Modern Materials

Question 1

What is the degree of unsaturation of the following molecule?

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

Answer 1

2

Question 2

Organic chemistry encompasses the chemistry of all ________

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

Answer 2

carbon compounds.

Question 3

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.

Answer 3

only carbon and hydrogen.

Question 4

What is the degree of unsaturation of the following molecule?

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

Question 5

Which of the following has the highest degree of unsaturation?

A)

B)

C)

D)

E)

Question 6

Which of the following statements regarding hydrocarbons is NOT correct?

A)Alkanes contain carbons that are sp hybridized.
B)Alkynes contain at least one carbon-carbon triple bond.
C)The carbons in the functional group characterizing an alkene are sp² hybridized.
D)The general chemical formula for alkanes is C_nH_2n+2.
E)The general formula for cycloalkanes is C_nH_2n.

Question 7

Iso-octane 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 8

Which of the following structures is an unsaturated hydrocarbon?

A)

B)

C)

D)

E)

Question 9

Of an unknown compound containing only carbon and hydrogen,0.123 moles was found to stoichiometrically react with 0.123 moles of hydrogen gas.Based on these 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 10

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

A)180 ^$\circ$ .
B)120 ^$\circ$ .
C)90 ^$\circ$ .
D)109.5 ^$\circ$ .
E)60 ^$\circ$ .

Question 11

Which of the following 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 are all true.

Question 12

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 13

When 1 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 14

A compound composed solely of carbon and hydrogen that is unsaturated could be ________.Choose the best answer.

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

Question 15

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 16

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

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

Question 17

Which of the following molecules is NOT considered "organic"?

A)CaC₂
B)CH₃NH₂
C)(CH₃)₂O
D)NaCH₃(CH₂)₄COO
E)(NH₂)₂CO

Question 18

Of an unknown compound containing only carbon and hydrogen,0.123 moles was found to stoichiometrically react with 0.246 moles of hydrogen gas.Based on these 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 19

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 20

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 21

What is the systematic name of the molecule shown?

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 22

Which one of the following is not a structural isomer of octane?

A)

B)

C)

D)

E)

Question 23

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.
E)It depends on the number of multiple bonds in the molecule.

Question 24

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 25

What is NOT a correct formula for the compound illustrated below?

A)CH₃(CH₂)₅CH₃
B)(CH₃)₂CHCH₂CH(CH₃)₂
C)CH₃CH(CH₃)CH₂CH(CH₃)CH₃
D)C₇H₁₆
E)

Question 26

What is the systematic name of the molecule shown?

A)4-methyl-5-isopropylheptane
B)3-propyl-4-methylheptane
C)2-methyl-3,4-diethylpentane
D)2,4-dimethyl-3-ethylheptane
E)3-ethyl-2,4-dimethylheptane

Question 27

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 28

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 29

Which of the following is a methyl group?

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

Question 30

What is the systematic name of the molecule shown?

A)3-methyl-5-butylheptane
B)2,4-diethyloctane
C)2-methyl-4-ethylhexane
D)3-methyl-5-ethylnonane
E)4-ethyl-7-methylnonane

Question 31

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 32

Which is NOT true about n-alkanes?

A)Their formulas are all C_nH_2n+2.
B)All 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 33

Which of the following 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 linear,some are branched,and some are cyclic at room temperature.
E)They have the formula C_nH_2n+2 if they are linear or branched or C_nH_2n if they are cyclic.

Question 34

Determine the number of carbons in the longest chain for the following molecule.

A)5
B)6
C)7
D)8
E)10

Question 35

What is the molecular formula for the compound illustrated below?

A)C₅H₈
B)C₅H₉
C)C₅H₁₀
D)C₅H₁₁
E)C₅H₁₂

Question 36

Which pair shows two different molecules?

A) CH₃(CH₂)₂C(CH₃)₃
B)
C)
D) (CH₃)₂CHCH(CH₃)CH(CH₃)₂
E)

Question 37

A primary difference between branched chain alkanes and normal alkanes is ________

A)the ratio of hydrogen to carbon.
B)the number of hydrogen atoms bonded to non-terminal carbon atoms.
C)the orbital hybridization of the carbon atoms.
D)the bond angles around each carbon atom.
E)the degree to which electrons are delocalized.

Question 38

In a hydrogenation experiment,50.00 grams of a straight-chain hydrocarbon containing 8 carbon atoms reacts with 1.829 grams of hydrogen gas.The hydrocarbon probably has the chemical formula ________

A)C₈H₁₈
B)C₈H₁₆
C)C₈H₁₄
D)C₈H₁₀
E)Insufficient information is provided.

Question 39

Determine the number of carbons in the longest chain for the following molecule .

A)6
B)7
C)8
D)9
E)10

Question 40

Which of the following pairs of molecules are NOT members of a homologous series?

A)
B)
C)
D)
E)

Question 41

For each of the numbered 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 42

Where is the carbon-carbon double bond in the hydrocarbon shown?

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

Question 43

Which of the following statements regarding the reactions of alkanes,alkenes,and alkynes is NOT correct?

A)The electrons in the $\pi$ bonds of alkenes and alkynes are more accessible to reactants than electrons in the $\sigma$ bonds in alkanes.
B)Alkenes and alkynes readily undergo addition reactions with molecules such as HCl,HBr,and HI.
C)An example of an addition reaction is H₂C=CH₂ + HCl $\to$ H₃C-CH₂Cl.
D)Alkenes and alkynes are important intermediates in the syntheses of other organic molecules.
E)Alkanes readily undergo addition reactions with highly reactive molecules such as F₂.

Question 44

Which of the following statements regarding alkenes and alkynes is NOT correct?

A)Alkenes and alkynes are typically present in large amounts in crude oil.
B)Alkenes are commonly derived from plant sources.
C)Alkynes are not common in nature due to the reactivity of the C C bond.
D)Alkanes can be dehydrogenated to give alkenes and alkynes.
E)Hydrocarbon reactivity increases in the order alkanes < alkenes < alkynes.

Question 45

How many structural (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 46

What is the molecular formula for the compound illustrated below?

A)C₅H₇
B)C₅H₈
C)C₅H₉
D)C₅H₁₀
E)C₅H₂₃

Question 47

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)(CH₃)₂CCH₂C(CH₃)₂

E)

Question 48

Crude oil is composed mostly of ________

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

Question 49

Name this molecule.

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

Question 50

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 non-terminal carbon atoms.
E)the degree to which electrons are delocalized.

Question 51

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.Which of the following is true?

A)The trans isomer is more polar.
B)The cis 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 52

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 53

What is the degree of unsaturation of the following molecule?

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

Question 54

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 55

Which of the following pairs show constitutional isomers?
I.
II.
III.
IV.

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

Question 56

What is the molecular formula for the following compound?

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

Question 57

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 58

Which of the following has the lowest ring strain?

A)

B)

C)

D)

E)

Question 59

Name this molecule.

A)1,2-methylcyclopentane
B)2-cyclopentylpropane
C)1,1-dimethylcyclopentane
D)2-cyclopentyl-3-methylethane
E)1,2-cyclomethylpentane

Question 60

Which of the following molecular structures is probably the most stable?

A)

B)

C)

D)

E)

Question 61

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 type of monomer unit.

Question 62

Which of the following structures represents cyclohexene?

A)

B)

C)

D)

E)

Question 63

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

A)

B)

C)

D)

E)

Question 64

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 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

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 67

How many structural isomers does toluene,C₆H₅CH₃,have?

A)None-i.e.,there is only 1 molecule
B)2
C)3
D)4
E)5

Question 68

Name the compound.

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

Question 69

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 70

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 cis-trans 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 71

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

Question 72

Which of the following shows a small section of polyethylene?

A)

B)

C)

D)

E)

Question 73

Are the methyl groups in xylene,C₆H₄(CH₃)₂,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 the aromatic system.
D)No,only the hydrogens in the ring are involved in the aromatic bonding.
E)No,only the carbon atoms in xylene are involved in aromatic bonding,not the hydrogens.

Question 74

Name the compound.

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

Question 75

Which of the following statements regarding addition polymers is NOT correct?

A)Polymers often do not have a sharp melting point.
B)Polymers cannot contain double bonds because they are too reactive.
C)Branched-chain polymers tend to be more flexible than straight-chain polymers.
D)Straight-chain polymers tend to have higher densities than branched-chain polymers.
E)Heteroatoms in polymers can drastically change the properties of a hydrocarbon polymer.

Question 76

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 77

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 not aromatic,but benzene is.
D)Cyclohexane has 12 hydrogen atoms in its structure,but benzene has 6 hydrogen atoms in its structure.
E)Cyclohexane is a combustible hydrocarbon,but benzene has such a stable aromatic structure that it does not burn.

Question 78

Which of the following is NOT a vinyl-based polymer?

A)

B)

C)

D)

E)

Question 79

What is another name for methylbenzene?

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

Question 80

Is cyclooctatetraene considered aromatic? The most stable structure at room temperature is shown.

A)Yes,because there are alternating single and double carbon-carbon bonds.
B)Yes,because the electrons in the $\pi$ bonds are delocalized over the ring structure.
C)Yes,there is an even number of electrons involved in $\pi$ bonding.
D)No,the electrons in the $\pi$ bonds are not delocalized over the ring structure.
E)No,the carbons are not sp² hybridized.