Mechanisms

Question 1

What is the general definition of an elimination reaction?

Answer 1

An elimination reaction is a chemical reaction in which two atoms or groups are removed from a molecule, resulting in the formation of a double bond or a ring structure.

Question 2

True or False: In an elimination reaction, a single product is always formed.

Answer 2

False

Question 3

True or False: Substitution reactions can only occur through a single mechanism.

Answer 3

False

Question 4

What are the two main types of substitution reactions?

Answer 4

Nucleophilic substitution and electrophilic substitution.

Question 5

Which type of reaction generally results in the formation of alkenes?

Answer 5

Elimination reactions

Question 6

What is a common characteristic of nucleophiles in substitution reactions?

Answer 6

Nucleophiles are electron-rich species that seek to donate their electrons.

Question 7

Products of reaction of halogenoalkane with warm NaOH

Answer 7

Alcohol, halide ion

Question 8

Products of reaction of halogenoalkane with 880-ammomia (concentrated and in excess)

Answer 8

Amine, halide ion

Question 9

Products of reaction of halogenoalkane with cyanide ions

Answer 9

Nitrile, halide ions

Question 10

How does reactivity of halogenoalkanes change?

Answer 10

Increases moving down the group

Question 11

Products of reaction of halogenoalkane with OH acting as a base (hot, reflux)

Answer 11

Alkene, water, halide ion

Question 12

How can you promote elimination with OH ions?

Answer 12

Use ethanol as a solvent
Heat under reflux
High temperature

Question 13

What is attacked by an OH ion in elimination of a halogenoalkane?

Answer 13

Hydrogen of a carbon next to the C-X bond

Question 14

How to form haloalkane from alkene?

Answer 14

React with H-X

Question 15

How to form dihaloalkane from alkene?

Answer 15

React with X-X, shake as layers may be immiscible

Question 16

How to form nitrile from haloalkane?

Answer 16

React with KCN in ethanolic conditions under reflux

Question 17

How to form alcohol from haloalkane?

Answer 17

React with NaOH in warm, aqueous conditions

Question 18

How to form amine from haloalkane?

Answer 18

React with 880-ammonia
(2 steps)

Question 19

How to form alkene from haloalkane?

Answer 19

React with NaOH in hot, ethanolic conditions under reflux

Question 20

How to form alkylhydrogensulfate from alkene?

Answer 20

React with cold, concentrated H2SO4

Question 21

How to form alcohol from alkene?

Answer 21

React with steam in the presence of an acid catalyst at 300°C and 60atm
OR
React with H2SO4 (cold, concentrated) then nucleophilic substitution with steam