Chapter 7: Carbon

Question 1

explain 4 properties of diamond

Answer 1

covalent network - carbons form in tetrahedral structure

hardness: single covalent bonds between carbon are strong.
sublimation: no small molecules only covalent bonds = sublimation
nonconductivity: no charged free moving particles present

thermal conductivity: compact and strong bonds between carbon atoms

Question 2

define allotrope

Answer 2

allotropes are made of the same element but with different chemical formulae and structures which results in different properties

allotropes of carbon are Buckyball’s, diamond, graphite and carbon nanotubes

Question 3

what is special about graphite’s structure

Answer 3

covalent layer lattice: it forms layers of strong covalent network bonds. The layers are held together by weak intermolecular (dispersion) forces. graphite layers can slide over each other making it slippery

conductivity: carbon atoms are bonded to 3 other carbon atoms and the fourth valence electron from each atom is able to move between layers and allow for electrical conductivity

Question 4

what are fullerenes

Answer 4

also known as Buckyball’s

C60

invented by Richard Buckminster Fuller

soccer ball like shape

carbon atoms are bonded to 3 others which leaves delocalised electrons from each atom

could be used in solar panels

Question 5

what is graphene

Answer 5

a single layer of graphite

very strong due to know weak dispersion forces between layers

retains electrical conductivity

Question 6

what is carbon nanotube

Answer 6

tube 1nm thick with walls formed by graphene

300x stronger than steel

conductors or semi conductors

strongly attracted to each other

thermal conductivity

Question 7

how is Volvo aiming to harness nanotubes

Answer 7

they are creating a car

steel replaced by nanotube sheets for stronger but lighter car

these nanotube sheets can be used as solar panel battery