organic chemistry board exam questions

8/10/2019 Organic Chemistry Board Exam Questions

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PreparedbyJEPaa/forBSChemGraduate2006

Organic

Chemistry

INSTRUCTION:Selectthecorrectanswerforeachofthefollowing

sections. Markonlyoneanswerforeachitembyshadingthebox

correspondingtotheletterofyourchoiceontheanswersheet

provided. STRICTLYNOERASURESALLOWED. Usepencilno.1only.

1. Inthenucleophilicaromaticsubstitutionreactionofnitrobenzene,

whichofthefollowingdoesnotapply?

a. Itisatwostepbimoleculardisplacement

b. Electronwithdrawinggroupsincreasetherateof

reaction

c.

Thetype

of

halide

does

not

affect

the

reaction

rate

d. Alargeisotopiceffectisobserved

2. ThedehydrationofalcoholinvolvesE1eliminationwiththe

formationofacarbonium(orcarbocation)ion. Thisoccursin:

a. Basicmedium

b.

Stronglybasicmedium

c.

Acidicmedium

d. pHisnotimportant

3. Forthechemicaltransformationofbenzamidetoaniline,the

reagents(s)neededis/are:

a. KMnO4

b. NaOH + Br2

c. NaNO2 + H2SO4

d.

Noneofthegivenanswers

4. Whydoelectronwithdrawingsubstitutentssuchasthehalogens

increasetheacidityofaceticacid?

a. Thehalogensstabilizethecarboxylateion

b. Thehalogensintensifythenegativechargeonthe

carboxylateion

c.

Thehalogens

destabilize

the

carboxylate

ion

d. Noneofthegivenanswers

5. Whichofthefollowingcompoundsformsthemoststable

carbocation?

a. Nitrobenzene

b. Aniline

c.

Toluene

d. Benzaldehyde

6. Thepropersequenceofeventstoconvertbenzenetombromo

nitrobenzeis:

a. Simultaneousbrominationandnitration

b. Brominationfollowedbynitration

c.

Nitrationfollowed

by

Friedel

Crafts

alkylation

and

bromination

d.

Nitrationfollowedbybromination

7. Thenitrationofbenzenedoesnotexhibitasignificantisotope

effectbecause:

a.

ACHbondisbrokenattheratedeterminingstep

b.

K1>K2

c. NoCHisbrokenattheratedeterminingstep


8. Whichofthefollowinggivesapositiveiodoformtest?

a. 3pentanone

b. Methanol

c. Ethanol

d.

tertbutylalcohol

9. Whatwouldbetheproduct(s)ofthereactionofethylbromide

andsodiumtertbutoxide?

a. 2methylpropaneandethanol

b. 2methylpropeneandethanol

c. Ethyltertbutylether

d.

Noneof

the

given

answers


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10.Predicttheorderofreactivitytowardsalkalinehydrolysisof(most

reactivefirst):

I.methylacetate, II.methylformate, III.methylpropionate

a. II > I > III

b.

II > III > Ic. I > II > III

d. III > I > II

11.Thehydrolysisofethylbenzoatelabeledwith18

O(CO18

O)yields

thefollowing:

a. Phenollabeledwith18

O

b.

Ethanollabeled

with

18O

c. Aceticacidlabeledwith18

O

d.

Benzoicacidlabeledwith18

O

12.Nylon66isformedfromadipicacidandhexamethylenediamine

by:

a.

Cationchainreactionpolymerization

b.

Freeradical

chain

reaction

polymerization

c. Stepreactionpolymerization

d. Anionchainreactionpolymerization

e. Noneofthese

13.ThereactivityoftheC=Ogroupinpropanalisprimarilydueto:

a. Abilityofoxygentoacquireelectrons

b. Inductiveeffectofneighboringgroups

c.

PolarityoftheC=Ogroupd. Noneofthese

14.Glycogenconsistsofmonomericunitsof:

a. Mannose

b. Galactose

c. Fructose

d.

Sucrose

e. Glucose

15.Whichcompounddoesnotcontainacarbonylgroup?

a. Ester

b. Ketone

c. Ether

d.

Carboxylicacid

16.IntheClaisencondensationofCH3COOC2H5andO

14C2H5ion,the

C14labelwillbedetectedinwhichproduct?

a. Ethylacetoacetate

b. Ethylacetate

c. Carbondioxide

d.

Ethanol

e. Noneofthese

17.Whichofthefollowingcandisrupthydrophobicbondsin

proteins?

a. Dichloroaceticacid

b.

Sodiumlaurylsulfate

c.

Mercaptoethanold. Dioxane

e. Nocorrectanswer

18.AKjeldahlnitrogenanalysisof4.27mgofnitrobenzenerequired

5.35mLof0.0150NHCltoneutralizetheammoniaproduced.

Calculatethe%nitrogeninthecompound.

a. 26%

b.

1.3%c. 13%

d. 2.6%

e. Noneofthegivenanswers

19.2OHbutanereactswithHClinthepresenceofzincchlorideand

understrongheat. Thefinalproductofthereaction:

a.

Hasaretention

of

configuration

b. Isracemic


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c. Hasinversionofconfiguration

d. Noneofthechoices

20.ApolypeptidechainistreatedwithLiAlH4,thenhydrolyzed,2

amino1propanolseparatesout. TheCterminalaminoacidofthepolypeptideis:

a. Alanine

b. Lysine

c. Praline


21.

Catalyticcracking

of

oil

directly

yields:

a. Alkenes

b.

Antiknockcompounds

c. Gasoline

d. Allofthese

22.

WhichofthefollowingcompoundsisthemostreactivebySN1

mechanism?a. Isopropylchloride

b. nbutylchloride

c. npropylchloride

d. tertbutylchloride

23.Whichofthefollowingaremanmadepolymers?

a. Silk

b.

Plastics

c. Lignin

d. Naturalrubber

e. Allarecorrectanswers

24.WhenCH3CO18

OHwasmadetoreactwithmethanol,themethyl

acetatewasfoundtocontainonlyordinaryO. Whichbondswere

broken?

a. COHofacidandCOHofalcohol

b. COHofacidandCOHofalcohol

c. COHofacidandCOHofalcohol

d. Noneofthese

25.

Whatcarboxylicacidispreparedfrompbromotoluenebyfreeradicalhalogenationfollowedbynitrilesynthesis?

a. pbromophthalicacid

b. pbromobenzoicacid

c. pbromophenylaceticacid

d. Noneofthese

26.

Inthe

conversion

of

acetyl

chloride

to

acetamide,

what

would

be

theeffectofelectronwithdrawingsubstitutentsonthe

tetrahedralintermediate?

a. Theystabilizethepartialchargeonoxygen

b. Theacylcompoundundergoesnucleophilicaddition

c. Theydestabilizethepartialchargeonoxygen

d.


27.Whatisthesubstrateoftrypsin?

a. Coconutoil

b. Starch

c. Noneofthegivenanswers

d. Protein

28.Howmanyisomericdisubstitutionproductsaretheoretically

possibleupon

the

bromination

of

benzene?

a. 2

b. 4

c. 3

d. 6

e. Noneofthechoices

29.

Cleavageof

isopropylphenylether

by

HBr

yields:

a. BenzeneandisopropylBr


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b. CHstretchingbandfortheboatformisathigher

wavenumber

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b. isopropylBrandphenol

c. bromobenzeneandisopropanol

d. noneofthesechoices

30.

Themajor

product

of

dehydrohalogenation

of

5Cl

2heptene

is:

a. 2,4heptadiene

b. Propanoicacidandbutenoicacid

c. 2,5heptadiene

d. Noneofthegivenchoices

31.Considerthechlorinationofmethaneinthepresenceoflight.

Oxygenacts

as

an

inhibitor

because

it

breaks

the

chain

reaction

by:

a.

Reactingwithmethane

b. Reactingwithchlorineatom

c. ReactingwithCl2


32.

Oxidationof

hexanol

by

acidic

dichromate

yields:

a. Hexanal

b. 2hexanone

c. Hexanoicacid


33.Predictthemajorproductofdehydrationof3OH3,4

dimethylhexane:

a.

3,4dimethyl

2hexene

b. 2,4dimethyl1hexene

c. 3,4dimethyl1hexene

d. 3,4dimethyl3hexene

34.TheIRspectrumofthechairformofcyclohexanediffersfromthat

oftheboatforminthefollowingaspect(s):

a.

CHstretching

bands

are

on

same

wavenumber

c. CHstretchingbandforchairformisathigher

wavenumber

d.

Noneof

the

given

answers

35.Enantiomersofmethylethylbutylaminearedifficulttoisolate

becauseof:

a. Conformation

b. Rotation

c. Inversion

d.

Noneof

these

36.

Asolutionofbromineincarbontetrachloridebecomescolorless

inthepresenceofethene. Theproductformedis:

a. Bromoethane

b. 1,2dibromoethane

c.

1,1,2,2tetrabromoethane

d.

Noneof

these

37.2OHbutanereactswithHClinthepresenceofzincchlorideand

understrongheat. Whatisthereactionmechanisminvolvedin

thisreaction?

a. E2

b. SN2

c. E1

d.

SN1

38.Ozonolysisof2methyl1,3butadieneyields:

a. Aldehydeandacids

b. Acids

c. Aldehydes

d. Noneofthechoices


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43.Inthehalogenationofalkanesatordinarytemperature,therate

ofabstractionofHfollowsthesequence3o > 2

o > 1

o. An

explanationforthistrendis:


39.Givetheproductofesterificationbetweenbenzoicacidand

ethanol.

a. Ethylbenzoate

b. Ethylbenzaldehyde

c.

Benzylacetate


40.TheBataanNuclearPowerPlantisbeingproposedforconversion

toacombinedcyclepowerplantusingnaturalgasasfuel. Natural

gasconsistsof:

a. Butane

b.

Methane

c. Ethane

d.

Noneofthese

41.TheIRspectrumofadilutesolutionofethanolshowsanOH

stretchingbandat3640cm1. Thisbandbecomesbroaderand

shiftsto3350cm1

astheethanolconcentrationisincrease.

Explain

this

shift.

a. HbondingtothesecondoxygenstrengthenstheOH

bond

b. Theenergyofvibrationisincreasedastheethanol

concentrationisincreased

c. HbondingtothesecondoxygenweakenstheOHbond


42.

Tertiaryalcohols

react

with

HX

via

SN2

mechanism.

The

feature(s)

ofthisreactionis(are):

a. Itisacidcatalyzed

b. Rearrangementispossible

c. Acarboniumionisformed

d. Allofthegivenanswers

a. Freeradicalfrom1oHismoststable

b.

Energyof

activation

is

lowest

in

3o

H

c. Theprobabilityofcollisionisgreatestbetweenhalogen

atomand3oH

d. Thecollisionfrequencyisgreatestbetweenthe

halogenatomandalkanewith3oH

44.Citereason(s)whyquarternaryammoniumsalts(A)withfour

differentgroups

attached

to

nitrogen

have

been

found

to

exist

as

configurationalenantiomerswhileenantiomersofsimpleamines

(B),alsowithfourdifferentgroupsattachedtothenitrogen,have

notbeenisolated.

a. Ahassp3orbitals

b. PositivechargeonquarternaryN

c.

UnsharedpairofelectronsonN

d.

Rapid

inversion

about

N

in

B


45.Whichofthefollowingcompoundsisthemostacidic?

a. Methylamine

b. Methane

c. Methylfluoride

d. Methylalcohol

46.Arrangethefollowinginorderofbasicity(mostbasicfirst):

I,methylfluoride; II,methylchloride; III,methylbromide;

IV,methyliodide.

a. I > II > III > IV

b. IV > III > II > I

c. I > III > II > IV

d.

Noneof

the

given

answers


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61.Thealdolcondensationreactionoftwomolesofacetaldehyde

withabasecatalystyields:

10


a. Equalamountsofisopropylbromideandnpropyl

bromide

b. npropylbromide

c. Isopropylbromide

d.

Noneof

the

given

answers

57.Whatchemicaltestswilldistinguish3chloropropenefromn

propylchloride? I,Br2inCCl4; II,KMnO4; III,CrO3; IV,H2SO4

a. I, II, IV

b. I, II, III

c. I, II, III, IV

d.

I,III


58.Inthereactionof1naphtholwithphenyldiazochloride,the

phenyldiazoniumionwillbindtowhichcarbonatomofthe

naphthalenemoiety?

a.

C7

b.

C

2

c. C5

d. C4

e. C8

59.Whatistheshapeofamethylradical?

a. Trigonal

b. Orthogonal

c.

Pyramidal

d. Noneofthegivenchoices

60.Whatistheshapeofanethylenemolecule?

a. Linear

b. Trigonal

c. Tetrahedral

d.

Pyramidal

a. 2OHbutanone

b. 3OHbutanal

c.

3OH

butanone

d. 2OHbutanal

62.Theisoelectricpointofserumalbuminis4.9. AtpH=7.0,which

ofthefollowingstatementswouldbetrue?

I,theproteinmovestothecathode

II,theproteinmovestotheanode

III,majority

of

its

ionizing

groups

are

basic

IV,majorityofitsionizinggroupsareacidic

a.

I, IV

b. II, III

c. I, III

d. II, IV

e.


63.Acidcatalyzedhydrolysisofethyleneoxideyields:

a. Ethyleneglycol

b. Ethanol

c. Carbondioxide

d. Noneofthese

64.Whatwouldbetheproductsofmildalkalinehydrolysisof1oleyl

2palmitoyl

3laurylglycerol?

a. Glycerol,sodiumlinoleate,sodiumpalmitate,sodium

laurate

b. Glycerol,sodiumoleate,sodiumpalmitate,sodium

laurate

c. Glycerol,oleicacid,palmiticacid,lauricacid

d. Glycerol,linoleicacid,palmiticacid,lauricacid

e.

Noneof

the

given

answers


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70.Arrangethefollowinginincreasingorderofdelocalizationof

electronsbyhyperconjugation(compoundswithgreatest

delocalizationofelectronsfirst):

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65.CompoundZformsaclearsolutionwithbenzenesulfonylchloride,

fromwhichaninsolublematerialseparatesoutuponacidification.

CompoundZis:

a. Ethylamine

b.

Methylethyl

amine

c. Trimethylamine


66.BrominationofisobuteneunderUVlightat127oCyields:

a. EqualamountsoftertbutylBrandisobutylBr

b. Isobutylbromideastheprimaryproduct

c.

Tertbutyl

bromide

as

the

primary

product

d. Noreaction

67.Hydrolysisoflauropalmitinyields:

a. Lauricacid,palmiticacidandglycerol

b. Onemoleculeeachoflauricacid,palmiticacid,and

glycerol

c.

Lauric

acid

and

palmitic

acid


68.Arrangethefollowingalcoholsinorderofreactivityinthe

esterificationofaceticacid(mostreactivefirst):

a. Methanol>npropyl=secbutyl>tert pentylalcohol

b. Methanol>npropyl>secbutyl>tert pentylalcohol

c. Tertpentylalcohol>secbutyl>npropyl>methyl

alcohol

d. Methanol=npropyl>secbutyl>tert pentylalcohol


69.Thebasicityofanilineisincreasedby:

a. COOH,halidegroups

b. Amino,methoxy,halidegroups

c.

Amino,methyl,

halide

groups

d. Noneofthese

a. tbutyl>isopropyl>ethyl>methyl

b.

tbutyl

>isopropyl

>ethyl

=methyl

c. methyl>ethyl>isopropyl>tbutyl

d. tbutyl=isopropyl>ethyl>methyl


71.Whichoftheindicatedbondshasthelowestbonddissociation

energy(D)?

a.

C6H5H

b. C6H5CH2CH3

c.

C6H5CH3

d. C6H5CH2H

e. AllhaveequalD

72.

Aproductdevelopmentmanagerwantsalowmolecularweight

polystyrene

product.

Given

the

chain

transfer

constants

of

severalchaintransferagents,whichofthesewouldbethemost

effectivetouse?

a. Benzene;0.02

b. Ethylbenzene;0.70

c. Toluene;0.20

d. Isopropylbenzene;1.00

73.

Thefollowing

compounds

are

used

as

Lewis

acid

catalysts

in

organicreactionsexcept:

a. BF3

b. AlCl3

c. CH3MgBr

d. SnCl4

74.

Thetotal

number

of

possible

structures

corresponding

to

the

formulaC4H9Iis:


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a. 7

b. 5

c. 4

d. 6

e.

Noneof

these

75.Byendgroupanalysis,thehydrolysisofonemoleculeof

completelymethylatedamylasegivesriseto:

a. EqualnumberoftetraOmethylDglucoseandtriO

methylDglucose

b. OnemoleculeoftetraOmethylDglucose

c.

Onemolecule

of

tri

O

methyl

D

glucose


76.Arrangethefollowinginorderofincreasingboilingpoint(lowest

boilingpointfirst):

I,butanal; II,butylalcohol; III,butanoicacid; IV,ethylether

a.

I, IV, II, III

b.

IV,

II,

I,

III

c. IV, I, II, III


77.Theeaseofabstractionofhydrogenatomsfromalkylhalides

followsthetrend: tertiaryH > secondaryH > primaryH. This

maybedueto:

a. ChangeintheRsubstituents

b.

Lengthof

the

R

substituents

c. Differencesinactivationenergies


78.Examinethestructureofthefollowingpolymerandidentifythe

monomericunit:(CH2CCl2CH2CCl2)n

a. 1,1dichloroethene

b.

Styrene

c. Vinylchloride


79.Whatisthemonomercomprisingtheplexiglass?

a. Ethyleneglycol

b.

Acrylonitrile

c. Methylmethacrylate

d. Adipicacid

e. Vinylacetate

80.Inthedehydrogenationof1pentene,platinum:

a. Lowerstheenergyofactivation

b.

Changesthe

net

energy

change

of

reaction

c. Shiftsthepositionofequilibrium

d.

Allofthese

81.Alcoholscanbeproducedbyreactingalkeneswith

hydroxymercurialcompoundsbyoxymercurationdemercuration

reaction. 2methyl1buteneyields:

a.

2

methyl

2

butanol

b. 2methyl1butanol

c. Amixtureof2methyl2butanoland2methyl1

butanol


82.AsubstituentRwhichwithdrawselectronsfromthecarbocation

hasthefollowingeffect:

a.

Itdestabilizes

the

cation

b. Itstabilizesthecation

c. Itmakesthecationstructuretetrahedral


83.Thistestwillshowwhetheranamineisprimary,secondary,or

tertiary:

a.

Periodictest

b. Sangerstest


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89.Whichofthefollowingconvertsacetaldehydetoaceticacid?

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c. Lucastest

d. Benedictstest

e. Hinsbergstest

84.

Whichamino

acid

provides

kinks

in

the

structure

of

proteins?

a. Cysteine

b. Cystine

c. Histidine

d. Proline

85.Thehydrolysisofonemoleofmannosegives:

a.

2moles

glucose

b. 1moleglucose+1molegalactose

c.

2molesGalactose

d. 1molefructose+1moleglucose

e. Noneofthese

86.

HClhasahigherbonddissociationenergythan:

a.

HBr

b. H2

c. HF

d. HOH

87.Thecarboxylateanioncontainssigmabondsthatutilize:

a. sp3orbitals

b. porbitals

c.

sporbitals

d. sp2orbitals

e. dorbitals

88.C6H12belongstoaseriesofhydrocarbonsknownas:

a. Arenas

b. Alkanes

c.

Alkenes

d. Alkynes

e. Nocorrectanswers

a. Sodiumborohydride

b.

Hydrogen/Ni

c. Potassiumpermanganate

d. Lithiumborohydride

e. Nametal

90.Whatisthemajorproduct(s)ofdehydrationof

(CH3)2C(OH)CH2CH3?

a.

CH2=CHCH3

b. CH2=C(CH3)CH2CH3

c.

(CH3)2C=CHCH3

d. (CH3)2CHCH=CH2


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