2.2 Structure & bonding of carbon

Question 1

Describe and explain the properties of diamond

Answer 1

● Four, strong covalent bonds for each carbon atom

● Very hard (strong bonds)

● Very high melting point (strong bonds)

● Does not conduct heat / electricity (no delocalised electrons)

Question 2

Describe and explain the properties of graphite

Answer 2

● Three covalent bonds for each carbon atom

● Layers of hexagonal rings

● High melting point

● Layers free to slide as weak intermolecular forces between layers; soft, can be used as a lubricant

● Conducts heat and electricity due to one delocalised
electron per carbon atom

Question 3

Describe and explain the properties of fullerenes

Answer 3

● Hollow shaped molecules

● Based on hexagonal rings but may have 5/7-carbon rings

● C60 has spherical shape, simple
molecular structure (Buckminsterfullerene)

Question 4

Describe and explain the properties of nanotubes

Answer 4

● Cylindrical fullerene with high length to diameter ratio

● High tensile strength (strong bonds)

● Electrical/thermal conductivity (delocalised electrons)

● Large surface area to volume ratio

Question 5

Describe and explain the properties of graphene

Answer 5

● A single layer of graphite.

● High tensile strength (strong bonds)

● Electrical/thermal conductivity (delocalised electrons)

● Large surface area to volume ratio

Question 6

What are giant covalent
structures? Give examples

Answer 6

● Solids, atoms covalently bonded together in a giant lattice.

● High melting/boiling points – strong covalent bonds.

● Mostly don’t conduct electricity (no delocalised e−)

● Diamond, graphite, silicon dioxide.