Question 1

In a halogenation reaction, how many halogen atoms are added to an alkyne with one triple bond when reacted with excess Br$$_2$$?

Accepted Answer

Four halogen atoms

Question 2

Which type of bond is targeted during halogenation reactions of alkenes and alkynes?

Accepted Answer

Double or triple bond

Question 3

What is the product when 2-butyne reacts with excess Cl$$_2$$?

Accepted Answer

2,2,3,3-tetrachlorobutane

Question 4

Given the reaction: H$$_2C=CH$_2 + Br$_2$$ $$\rightarrow$$ ?, what is the name of the product?

Accepted Answer

1,2-dibromoethane

Question 5

Which of the following best describes the halogenation reaction of an alkyne with one equivalent of Br$$_2$$?

Accepted Answer

A dihalide is formed at the carbons of the triple bond

Question 6

If you react 3-hexyne with excess Cl$$_2$$, what is the major product?

Accepted Answer

3,3,4,4-tetrachlorohexane

Question 7

Which statement is TRUE about halogenation of alkenes?

Accepted Answer

Halogenation adds two halogen atoms across the double bond

Question 8

What is the correct balanced equation for the halogenation of ethyne (acetylene) with excess Br$$_2$$?

Accepted Answer

$$\mathrm{HC\equiv CH} + 2\ \mathrm{Br}_2 \rightarrow \mathrm{HBr}_2C-$$CHBr_2$$

Question 9

A student reacts 2-methyl-2-butene with Cl$$_2. $$What is the expected product?

Accepted Answer

2,3-dichloro-2-methylbutane

Question 10

Which of the following is a correct description of the halogenation reaction mechanism for alkenes?

Accepted Answer

Halogen molecules add across the double bond, forming a vicinal dihalide

Question 11

What is the IUPAC name for the product formed when 2,3-dimethyl-2-butyne reacts with excess Br$$_2$$?

Accepted Answer

2,2,3,3-tetrabromo-2,3-dimethylbutane

Question 12

Which reagent is commonly used for halogenation reactions of alkenes and alkynes?

Accepted Answer

Br$$_2 or Cl$_2$$

Question 13

During halogenation of an alkyne, what is the product if only one equivalent of Br$$_2 is $$used?

Accepted Answer

A dihalide with halogens on adjacent carbons

Question 14

Which of the following best explains why halogenation reactions are important in organic chemistry?

Accepted Answer

They allow for the introduction of functional groups that can be further modified

Question 15

A chemist adds Cl$$_2 to 1-$$pentyne. What is the major product if excess Cl$$_2 is $$used?

Accepted Answer

1,1,2,2-tetrachloropentane

Question 16

Which of the following is the correct general equation for the halogenation of an alkene?

Accepted Answer

$$\mathrm{RCH=CHR} + X_2$ \rightarrow \mathrm{RCHX-CHXR}$$

Question 17

What is the product when 1-butene reacts with Br$$_2$$?

Accepted Answer

1,2-dibromobutane

Question 18

Which of the following is NOT a product of halogenation of an alkene?

Accepted Answer

A tetrahalide

Question 19

A patient is exposed to vinyl chloride (H$$_2C=$$CHCl). If this compound undergoes halogenation with Br$$_2$$, what is the expected product?

Accepted Answer

1,2-dibromo-1-chloroethane

Question 20

Which statement best describes the difference between halogenation of alkenes and alkynes?

Accepted Answer

Alkynes can add two equivalents of halogen to form tetrahalides, while alkenes add one equivalent to form dihalides

Halogenation Reactions of Alkenes and Alkynes

Study Guide - Practice Questions