Topic 2: Structure

Question 1

Structure of Graphite

Answer 1

Giant covalent structure
Each carbon forms 3 bonds, with a delocalised electron.
There are strong covalent bonds between carbon atoms, yet weak intermolecular forces between the layers - they easily slide over each other.
Delocalised electrons allow graphite to conduct electricity, as the electrons can carry a charge.
Insoluble, soft, slippery

Question 2

Structure of Diamond

Answer 2

Each carbon forms 4 bonds
Tightly packed rigid arrangement allows heat to be conducted well.
High melting point due to many strong covalent bonds.
Does not conduct electricity as it has no delocalised electrons.
Insoluble,

Question 3

Uses of diamond

Answer 3

Very strong structure, so can be used to cut gemstones

Question 4

Structure of Graphene

Answer 4

One layer of graphite - 1 atom thick
Very lightweight
Conducts electricity as the delocalised electrons are free to carry the charge. The electrons also strengthen the covalent bonds - making it very strong

Question 5

Uses of Graphene

Answer 5

• Aircraft shells
• Super computers and high speed computing
• Smart phone screens

Question 6

Where are giant lattices present?

Answer 6

1. Ionic solids -> Giant ionic lattices
2. Covalently bonded solids -> e.g. diamond
3. Solid metals -> Giant metallic lattices

Question 7

Describe an ionic lattice

Answer 7

• Evenly distributed crystalline structure
• Ions arranged in a regular repeating pattern
• The attraction occurs in all directions
• Overall charge of 0

Question 8

Describe a metallic lattice

Answer 8

• The metal ions are surrounded by a ‘sea’ of delocalised electrons

Question 9

Describe a covalent lattice

Answer 9

They can be either simple or giant molecular lattices

Question 10

Give examples of simple covalent lattices

Answer 10

Iodine - I2
Ice - H2O
Buckminsterfullerene - C60

Question 11

Give examples of giant covalent lattices

Answer 11

Silicon (VI) oxide
Diamond
Graphite