Ch. 11.5: Intro To Reaction Mechanisms

Question 1

Describe homomlytic fission

Answer 1

When a covalent bond breaks this way, each of the bonded atoms takes one of the shared pair of electrons from the bond.

Each atom now has a single unpaired electron.

An atom or group of atoms with an unpaired electron is called a radical.

Question 2

Describe heterocyclic fission

Answer 2

When a covalent bond breaks this way, one of the bonded atoms takes both of the electrons from the bond.

The atom that takes both electrons becomes a negative ion.

The atom that does not take the electrons becomes a positive ion.

Question 3

Define reaction mechanism

Answer 3

It shows you how the reaction takes place. It is a step by step sequence of chemical reactions that lead to an overall chemical reaction.

Question 4

What do curly arrows represent in reaction mechanisms?

Answer 4

They show :

• movement of electrons
• where bonds are broken
• where bonds are made

Question 5

What are the three types of reaction?

Answer 5

Addition
Substitution
Elimination

Question 6

Describe an addition reaction

Answer 6

Two reactants join together to form one product

Question 7

Describe a substitution reaction

Answer 7

An atom or group of atoms is replaced by a different atom or group of atoms. The amount of reactants and products stay the same.

Question 8

Describe an elimination reaction

Answer 8

This is when a small molecule is removed from a larger one resulting in two products.