Synthesis

Question 1

What is the process of bond breaking known as?

Answer 1

Bond fission

Question 2

What are the two types of bond fission?

Answer 2

Homolytic and heterolytic

Question 3

Homolytic fission:

Answer 3

• results in the formation of two neutral radicals
• occurs when each atom retains one electron from the covalent
  sigma bond and the bond breaks evenly
• normally occurs when non-polar covalent bonds are broken

Question 4

Why is homolytic fission inappropriate for organic synthesis?

Answer 4

Reactions involving homolytic fission tend to result in the formation of
very complex mixtures of products

Question 5

Heterolytic fission:

Answer 5

• results in the formation of two oppositely charged ions
• occurs when one atom retains both electrons from the sigma
  covalent bond and the bond breaks unevenly
• normally occurs when polar covalent bonds are broken

Question 6

Single headed arrow…

Answer 6

Indicates the movement of a single electron

Question 7

Double headed arrow…

Answer 7

Indicates the movement of an electron pair

Question 8

Tail of the arrow…

Answer 8

Shows the source of electrons

Question 9

Head of the arrow…

Answer 9

Shows the destination of electrons

Question 10

Two single-headed arrows starting at the middle of a covalent bond…

Answer 10

Indicates that homolytic fission is occuring

Question 11

A double-headed arrow starting at the middle of a covalent bond…

Answer 11

Indicates that heterolytic fission is occuring

Question 12

An arrow drawn with the head pointing to the space between two atoms…

Answer 12

Indicates that a covalent bond will be formed between those two atoms

Question 13

Nucleophiles:

Answer 13

• negatively charged ions or neutral molecules that are electron
  rich, such as Cl, Br, OH, CN, NH3 and H2O
• attracted towards atoms bearing a partial delta+ or full positive
  charge
• capable of donating an electron pair to form a new covalent bond

Question 14

Electrophiles:

Answer 14

• positively charged ions or neutral molecules that are electron
  deficient, such as
  H+, NO2+, and SO3
• attracted towards atoms bearing a partial delta− or full negative
  charge
• capable of accepting an electron pair to form a new covalent bond

Question 15

What reaction types can be identified from a chemical
equation?

Answer 15

• substitution
• addition
• elimination
• condensation
• hydrolysis
• oxidation
• reduction
• neutralisation