Alkenes and Alkynes: Structure, Properties, and Reactions

Question 1

Which of the following is the correct IUPAC name for the following compound: CH3CH=CHCH2CH2CH3?

Accepted Answer

2-hexene

Answer

3-hexene

Answer

2-methyl-3-hexene

Answer

4-hexene

Question 2

Which of the following compounds is an alkyne?

Accepted Answer

CH3C≡CH

Answer

CH3CH=CH2

Answer

CH3CH2CH3

Answer

CH2=CHCH=CH2

Question 3

According to IUPAC nomenclature, what is the name of the alkyne with the molecular formula CH3CH2C≡CCH2CH3?

Accepted Answer

3-hexyne

Answer

1-hexyne

Answer

2-hexyne

Answer

4-hexyne

Question 4

Which reaction is commonly used to synthesize alkynes?

Accepted Answer

Dehydrohalogenation of alkenes

Answer

Alkylation of alkynes

Answer

Hydroboration-oxidation of alkenes

Answer

Wittig reaction

Question 5

Predict the major product of the hydroboration-oxidation of 1-butene.

Accepted Answer

1-butanol

Answer

2-butanol

Answer

1-butene oxide

Answer

2-butene oxide

Question 6

Which of the following is NOT a characteristic of an alkene?

Accepted Answer

Boils at a higher temperature than alkanes of similar molecular weight

Answer

Contains one or more carbon-carbon double bonds

Answer

Classified as an aliphatic hydrocarbon

Answer

Typically more reactive than alkanes

Question 7

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

Accepted Answer

sp2

Answer

sp

Answer

sp3

Answer

sp3d

Question 8

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

Accepted Answer

sp

Answer

sp2

Answer

sp3

Answer

sp3d

Question 9

What type of reaction occurs when hydrogen is added to an alkene?

Accepted Answer

Addition

Answer

Substitution

Answer

Elimination

Answer

Rearrangement

Question 10

In an alkyne, which hydrogen exhibits the most acidic character?

Accepted Answer

Terminal hydrogen

Answer

Internal hydrogen

Answer

Both terminal and internal hydrogens

Answer

None of the hydrogens

Question 11

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

Accepted Answer

sp2

Answer

sp

Answer

sp3

Answer

sp3d

Question 12

Which product is formed when an alkene reacts with a hydrogen halide?

Accepted Answer

Alkyl halide

Answer

Alkenyl halide

Answer

Alkyl alcohol

Answer

Alkenyl alcohol

Question 13

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 14

Which product is formed when an alkyne reacts with a hydrogen halide?

Accepted Answer

Alkynyl halide

Answer

Alkyl halide

Answer

Alkenyl halide

Answer

Alkenyl alcohol

Question 15

Which of the following is NOT a characteristic of alkenes?

Accepted Answer

They are saturated hydrocarbons

Answer

They obey the general formula CnH2n

Answer

They contain carbon-carbon double bonds

Answer

They are unsaturated aliphatic hydrocarbons

Question 16

Predict the product of the following reaction: 1-butene + H2 -> ?

Accepted Answer

Butane

Answer

1-Butanol

Answer

2-Butene

Question 17

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

Accepted Answer

sp2

Answer

sp3

Answer

sp

Answer

sp3d

Question 18

Which of the following is a common method for the synthesis of alkenes?

Accepted Answer

Dehydration of alcohols

Answer

Hydrolysis of esters

Answer

Reduction of aldehydes

Answer

Oxidation of ketones

Question 19

Which of the following statements about the stability of alkenes is true?

Accepted Answer

Alkenes with more alkyl substituents on the double bond are more stable

Answer

Alkenes with internal double bonds are more stable than alkenes with terminal double bonds

Answer

Alkenes with less alkyl substituents on the double bond are more stable

Question 20

Which of the following reactions is a characteristic of alkenes?

Accepted Answer

Addition

Answer

Substitution

Answer

Condensation

Answer

Elimination

Question 21

What type of hybridization is present at the carbon-carbon double bond in an alkene?

Accepted Answer

sp²

Answer

sp

Answer

sp³

Answer

sp³d

Question 22

Which of the following is a physical property of alkenes?

Accepted Answer

Lower boiling point than alkanes with the same number of carbon atoms

Answer

Solubility in polar solvents

Answer

Solid state at room temperature

Answer

Higher density than water

Question 23

Identify the functional group present in an alkyne:

Accepted Answer

Carbon-carbon triple bond

Answer

Carbon-carbon double bond

Answer

Nitrogen-hydrogen bond

Answer

Carbon-oxygen double bond

Question 24

Which of the following is a characteristic of alkynes?

Accepted Answer

Linear geometry due to sp hybridization of carbon atoms in the triple bond

Answer

Trigonal planar geometry

Answer

Tetrahedral geometry

Question 25

What type of hybridization is present at the carbon-carbon triple bond in an alkyne?

Accepted Answer

sp

Answer

sp³

Answer

sp³d

Answer

sp²