Chapter 6 - Organic Halogen Compounds

Question 1

Alkyl halides undergo what reaction?

Answer 1

Nucleophilic substitution reactions

Question 2

Reaction in which a nucleophile displaces the halide leaving group from the alkyl halide substrate.

Answer 2

Nucleophilic substitution reactions

Question 3

Why nucleophilic substitution reversible?

Answer 3

because the leaving group also has an unshared electron pair

Question 4

What are the most common nucleophiles? (5)

Answer 4

oxygen, nitrogen, sulfur, halogen, and carbon nucleophiles

Question 5

Two main nucleophilic substitution mechanisms

Answer 5

Sn2 and Sn1

Question 6

A one-step process in which the bond to the leaving group begins to break as the bond to the nucleophile begins to form

Answer 6

Sn2 mechanism

Question 7

3 steps of Sn2 mechanism

Answer 7

1. Backside attack
2. Both partly bonded
3. the nucleophile supplies another electron pair to the carbon atom as the leaving group departs

Question 8

What molecules are involved in the key step of Sn2? (2)

Answer 8

1. Nucleophile
2. Substrate

Question 9

True or False:

Every SN2 displacement occurs with inversion of
configuration.

Answer 9

True

Question 10

True or False:

The reaction is fastest when the alkyl group of the substrate is methyl or primary and
Slowest (usually not at all) when it is tertiary.

Answer 10

True

Question 11

a two-step process where the bond between the carbon and the leaving group breaks first and then the resulting carbocation combines with the nucleophile.

Answer 11

Sn1 mechanism

Question 12

Sn1 mechanism involves this reactant

Answer 12

Substrate only

Question 13

True or False:

The rate of the reaction does depend on the concentration of the nucleophile in Sn1 mechanism.

Answer 13

False
(Does not depend)

Question 14

When is Sn1 reaction fastest?

Answer 14

when the alkyl group of the substrate is tertiary

Question 15

When is Sn1 slowest?

Answer 15

when the alkyl group of the substrate is primary

Question 16

These are solvents such as water or alcohols that can donate protons

Answer 16

Polar protic solvents

Question 17

These are solvents such as acetone, dimethyl sulfoxide that cannot donate protons

Answer 17

Polar aprotic solvents

Question 18

True or False:

If the nucleophile is weak, the SN2 mechanism will be favored

Answer 18

False
(If the nucleophile is strong)

Question 19

Mechanism where a hydrogen atom and a halogen atom from adjacent carbons are eliminated and a carbon–carbon double bond is formed.

Answer 19

Elimination (or dehydrohalogenation)

Question 20

A one step process where HX is eliminated and a C=C bond is formed in the same step

Answer 20

E2 mechanism

Question 21

A two-step process and has the same first step as the SN1 mechanism

Answer 21

E1 mechanism

Question 22

In tertiary halides, substitution can only occur by what mechanism?

Answer 22

SN1 mechanism

Question 23

In tertiary halides, elimination can occur by what mechanism?

Answer 23

E1 or E2 mechanism

Question 24

True or False:

With weak nucleophiles and polar solvents - the SN1 and E1 mechanisms compete with each other

Answer 24

True

Question 25

Only possible mechanism in primary halides (2)

Answer 25

SN2 and E2 mechanisms

Question 26

What reactions are possible in secondary halides?

Answer 26

SN2, SN1, E2, E1

Question 27

Compounds used in dry cleaning and as degreasing agents in metal and textile processing (2)

Answer 27

Trichloroethylenes and tetrachloroethylenes

Question 28

are polyhalogenated compounds containing chlorine and fluorine.

Answer 28

Chlorofluorocarbons