Unit 3

Question 1

What are halo alkanes?

Answer 1

Question 2

What are the reactions of monohaloalkanes?

Answer 2

Elimination
Nucleophillic substitutuon to form alkanols
Nucleophillic substitution to form ethers
Nucleophillic substitution to form nitriles

Question 3

Nucleophillic substition of monohaloalkanes
(Formation of ethers)

Answer 3

Alkoxide ion formed by reacting Na with alkanol.

Nucleophillic attack on delta + C of C-Cl bond

Question 4

Nucleophillic substitution of monohaloalkanes to form alkanols

Answer 4

React with acqueous alkalis

Question 5

Nucleophillic substitution of monohaloalkanes to form nitriles

Answer 5

Ethanolic cyanide
Nitriles can be acid hydrolysed to carboxyllic acids

Question 6

Which type of substitution reactions do primary haloalkanes undergo?

Answer 6

Sn2 due to

Less steric hindrance

Primary carbocation needed for Sn1 is not stable

Question 7

What type of substitution reactions do tertiary haloalkanes undergo?

Answer 7

Sn1 due to
Steric hindrance from bulky side groups blocking nucleophile

Inductive stabilisation of carbocation intermediate from alkyl groups

Question 8

Mechanism of Sn1

Answer 8

Question 9

Mechanism of Sn2

Answer 9

Question 10

Dehydration of alkanols

Answer 10

Question 11

Structure of benzene

Answer 11

Question 12

Substitution reactions of benzene

Answer 12

Question 13

Nitration of benzene

Answer 13

Question 14

Alkylation of benzene

Answer 14

Question 15

Halogenation of benzene

Answer 15

Question 16

What is a chromophore?

Answer 16

A group of atoms within a molecule that is reaponsible for absorbing light in the visible region of the spectrum.

Question 17

Where do chromophores exist?

Answer 17

In a conjugated system

Question 18

What is a conjugated system?

Answer 18

A system of adjacent unhybridised p orbitals that overlap side on

Question 19

What is connection between HOMO and LUMO and wavelength

Answer 19

The greater the difference the smaller the wavelength

Question 20

How can alkenes be prepared from monohaloaljanes?

Answer 20

Base induced elimination

Question 21

How are dihaloalkanes formed

Answer 21

Question 22

How are monohaloalkanes formed?

Answer 22

Question 23

What are amines?

Answer 23

Question 24

Heterolytic v homolytic fission

Answer 24

Heterolytic dission
gives far fewer products
better suited for organic synthesis

Question 25

What is a nucleophile?

Answer 25

Species which are attracted towards atoms bearing a partial or full positive charge.

Question 26

What is an electrophile?

Answer 26

Electropholes are species which are attracted towards atoms with a partial or full negative charge.