Alkenes and Alkynes: Structure, Properties, and Reactions

Question 1

Design a synthesis of cis-2-butene starting from ethyne and any necessary inorganic reagents.

Accepted Answer

Ethyne + HBr → vinyl bromide → cis-2-butene

Answer

Ethyne + H2 → cis-2-butene

Answer

Ethyne + Br2 → 1,2-dibromoethane → cis-2-butene

Question 2

Which of the following is a characteristic reaction of alkenes and alkynes?

Accepted Answer

Addition

Answer

Substitution

Answer

Elimination

Answer

Rearrangement

Question 3

Which functional group has the following hybridization: sp²?

Accepted Answer

Alkene

Answer

Alkane

Answer

Alkyne

Answer

Alcohol

Question 4

What is the IUPAC name of the following compound: CH3-CH=CH-CH2-CH3?

Accepted Answer

1-Pentene

Answer

2-Pentene

Answer

3-Pentene

Answer

4-Pentene

Question 5

Which of the following is the strongest acid?

Accepted Answer

Ethyne

Answer

Ethane

Answer

Ethene

Answer

Ethanol

Question 6

What is the hybridization of the carbon atoms in the triple bond of an alkyne?

Accepted Answer

sp

Answer

sp²

Answer

sp³

Answer

sp³d

Question 7

Which reagent is used to selectively convert an alkyne to a cis-alkene?

Accepted Answer

H2, Lindlar's catalyst

Answer

H2, Ni catalyst

Answer

NaBH4

Answer

KMnO4

Question 8

Which reaction is commonly employed to synthesize alkynes?

Accepted Answer

Elimination reaction of vicinal dihalides with a strong base

Answer

Dehydration of alcohols

Answer

Reduction of alkenes

Question 9

Which of the following reactions is characteristic of alkynes but not alkenes?

Accepted Answer

Polymerization

Answer

Addition of HX

Answer

Addition of H2

Answer

Combustion

Question 10

What is the hybridization of the carbon atoms in the double bond of an alkene?

Accepted Answer

sp2

Answer

sp

Answer

sp3

Answer

sp3d

Question 11

Which of the following alkenes is most stable?

Accepted Answer

Ethene

Answer

Propene

Answer

1-Butene

Answer

2-Butene

Question 12

What is the mechanism of the following reaction: HC≡CH + H2 → CH3CH3?

Accepted Answer

Radical addition

Answer

Electrophilic addition

Answer

Nucleophilic addition

Answer

Pericyclic addition

Question 13

Which of the following alkenes can undergo Diels-Alder cycloaddition?

Accepted Answer

1,3-Butadiene

Answer

Ethene

Answer

Propene

Answer

2-Butene

Question 14

Which of the following functional groups is characteristic of alkenes?

Accepted Answer

Double bond

Answer

Carbonyl

Answer

Alcohol

Answer

Ether

Question 15

What is the hybridization of the carbon atoms involved in a double bond?

Accepted Answer

sp2

Answer

sp

Answer

sp3

Answer

sp3d2

Question 16

What is the product of the hydroboration-oxidation reaction of an alkene?

Accepted Answer

Alcohol

Answer

Ketone

Answer

Alkyl halide

Answer

Carboxylic acid

Question 17

Which of the following compounds is an alkyne?

Accepted Answer

Butyne

Answer

Ethene

Answer

Propene

Answer

Pentane

Question 18

Which of the following reactions is NOT characteristic of alkynes?

Accepted Answer

Nucleophilic substitution

Answer

Addition

Answer

Electrophilic addition

Answer

Hydrohalogenation

Question 19

What is the product of the catalytic hydrogenation of an alkyne?

Accepted Answer

Alkane

Answer

Alkene

Answer

Alkyl halide

Answer

Alcohol

Question 20

Which of the following is a characteristic structural feature of alkenes?

Accepted Answer

наличието на една или повече въглерод-въглеродни двойни връзки

Answer

наличие на молекулна формула CnH2n

Answer

проявяват цис-транс изомеризъм

Answer

циклична структура

Question 21

Каква е хибридизацията на въглеродните атоми, участващи в двойната връзка въглерод-въглерод в алкените?

Accepted Answer

sp2

Answer

sp

Answer

sp3

Answer

sp3d

Question 22

Кое от следните съединения е алкин?

Accepted Answer

Бутин

Answer

Етен

Answer

Пропен

Answer

пентан

Question 23

Какъв е продуктът от каталитичното хидриране на алкин?

Accepted Answer

алкан

Answer

алкен

Answer

алкохол

Answer

кетон

Question 24

Кое от следните твърдения за стабилността на алкените е вярно?

Accepted Answer

алкените с повече заместени двойни връзки са по-стабилни

Answer

алкените с по-малко заместени двойни връзки са по-стабилни

Answer

заместеността не повлиява стабилността на алкените

Answer

нито едно от горните

Question 25

Кой е основният продукт от киселинно-катализираната хидратация на алкен?

Accepted Answer

алкохол

Answer

кетон

Answer

алдехид

Answer

карбоксилна киселина

Question 26

Кое от следните е практическо приложение на алкените?

Accepted Answer

всички изброени

Answer

производство на пластмаси

Answer

синтез на горива

Answer

производство на синтетичен каучук

Question 27

Which alkene is most stable?

Accepted Answer

2-Methyl-2-butene

Answer

2-Methyl-1-butene

Answer

1-Butene

Answer

2-Butene

Question 28

Which reaction is NOT characteristic of alkenes?

Accepted Answer

Substitution of hydrogen

Answer

Addition of hydrogen

Answer

Addition of bromine

Answer

Polymerization

Question 29

Which of the following is an alkyne?

Accepted Answer

CH₃C≡CH

Answer

CH₃CH=CH₂

Answer

CH₃CH₂CH₃

Answer

CH₃CHOHCH₃

Question 30

What is the major product of the following reaction: CH₃CH₂CH=CH₂ + HCl →

Accepted Answer

CH₃CH₂CH(Cl)CH₃

Answer

CH₃CH(Cl)CH₂CH₃

Answer

CH₃CH₂CH₂CH₂Cl

Answer

CH₃CHClCH₂CH₃

Question 31

What is the hybridization of the carbon atoms in an alkene?

Accepted Answer

sp2

Answer

sp

Answer

sp3

Answer

sp3d

Question 32

Which alkene reacts most readily with an electrophile?

Accepted Answer

2-Methylpropene

Answer

Ethylene

Answer

Propylene

Answer

1-Butene

Question 33

Which reaction can be used to prepare an alkyne?

Accepted Answer

Elimination of a hydrogen halide from a vic-dihalide

Answer

Addition of a hydrogen halide to an alkyne

Answer

Hydrolysis of an ester

Answer

Oxidation of an alcohol

Question 34

Which of the following reactions is characteristic of alkenes?

Accepted Answer

Addition reactions

Answer

Substitution reactions

Answer

Esterification reactions

Answer

Neutralization reactions

Question 35

Which alkene exhibits the highest boiling point?

Accepted Answer

Trans-2-butene

Answer

Ethene

Answer

Propene

Answer

Cis-2-butene

Question 36

In the presence of a nickel catalyst, what is the product of the reaction between propene and hydrogen?

Accepted Answer

Propane

Answer

Propyne

Answer

Propyl alcohol

Answer

Propylene glycol

Question 37

Which of these alkenes can participate in a Diels-Alder cycloaddition?

Accepted Answer

1,3-Butadiene

Answer

Ethene

Answer

1-Butene

Answer

2,2-Dimethylpropene

Question 38

What is the hybridization of a carbon atom involved in an alkyne's triple bond?

Accepted Answer

sp

Answer

sp2

Answer

sp3

Answer

sp3d

Question 39

Which of the following is the correct general formula for alkenes?

Accepted Answer

CnH2n

Answer

CnH2n-2

Answer

CnH2n+2

Answer

CnH2n-4

Question 40

The IUPAC name of the alkene CH3-CH=CH-CH2-CH3 is:

Accepted Answer

2-pentene

Answer

1-pentene

Answer

3-pentene

Answer

4-pentene

Question 41

Which hybridization describes the carbon atoms involved in the double bond of an alkene?

Accepted Answer

sp2

Answer

sp3

Answer

sp3d

Answer

sp

Question 42

Which physical property is characteristic of alkenes?

Accepted Answer

Lower boiling points than alkanes

Answer

Higher density than alkanes

Answer

More soluble in water than alkanes

Answer

Solid at room temperature

Question 43

The major product of the electrophilic addition of a halogen to an alkene is a:

Accepted Answer

Vicinal dihalide

Answer

Alkyl halide

Answer

Alkenyl halide

Answer

Alkyl radical

Question 44

The general formula for alkynes is:

Accepted Answer

CnH2n-2

Answer

CnH2n

Answer

CnH2n-4

Answer

CnH2n+2

Question 45

An example of a hydration reaction of alkynes is:

Accepted Answer

Reaction with water in the presence of a catalyst

Answer

Reaction with hydrogen

Answer

Reaction with sodium

Answer

Reaction with carbon dioxide

Question 46

The carbon atoms involved in the triple bond of an alkyne exhibit which hybridization?

Accepted Answer

sp

Answer

sp2

Answer

sp3d

Answer

sp3