Giant covalent substances

Question 1

Name 3 giant covalent lattices

Answer 1

Graphite
Graphene
Diamond

Question 2

Describe the structure of graphite

Answer 2

Each graphite carbon atom is covalently bonded to 3 other carbon atoms
In hexagonal arrangements in layers
Each carbon atom has 4 electrons for bonding
3 used for forming covalent bonds
1 is delocalised between layers

Question 3

Describe the structure of graphene

Answer 3

Differs from graphite as it is a single layer of carbon atoms
Each carbon atom is covalently bonded to 3 others
Contains mobile delocalised electrons
Has a trigonal planar arrangement of atoms

Question 4

Describe the structure of diamond

Answer 4

Each atom is covalently bonded to 4 other carbon atoms
In a tetrahedral arrangement
Do not contain delocalised electrons

Question 5

Describe the melting point of giant covalent lattices

Answer 5

Held together by strong covalent bonds
Require a large amount of energy to break
High melting and boiling points

Question 6

Describe the solubility of giant covalent lattices

Answer 6

Do not interact with water molecules so are insoluble in water

Question 7

Describe the conductivity of giant covalent lattices

Answer 7

Do not contain mobile charged particles
Do not conduct electricity
Exceptions: graphite & graphene both contain mobile delocalised electrons & can conduct electricity