Covalent Bonding Flashcards
what does a single covalent bond contain
a shared pair of electrons
what do multiple covalent bonds contain
multiple shared pairs of electrons
describe the macromolecular (giant covalent) structure
- huge network of covalently bonded atoms
give two examples of macromolecular structures
diamond
graphite
describe the structure of graphite
- macromolecular structure
- carbon atoms arranged in sheets of flat hexagons > three covalent bonds per carbon atom
- fourth outer electron is delocalised
- sheets of hexagons are bonded together with weak van der Waal forces
why can graphite be used as a lubricant and why is it slippery
- weak bonds between the hexagon sheets can easily be broken so the sheets can slide over eachother
does graphite conduct electricity and why
yes
- the delocalised electrons are free to move along the sheets so electric current can flow
why can graphite be used to make lightweight sports equipment / have a low density
layers are far apart compared to the length of the covalent bonds > has a low density
describe melting point of graphite and why
very high
- has strong covalent bonds that take a lot of energy to break
is graphite soluble and why
no its not
- the covalent bonds are too hard to break
derive structure of diamond
macromolecular structure
- made up of carbon atoms
- each carbon atom is bonded to another four carbon atoms (covalently)
- tetrahedral shape > crystal lattice structure
describe mpt of diamond and why
very high
- strong cov bonds which take a lot of energy to break
is diamond a conductor of thermal and why
yes
- vibrations travel easily through the stiff lattice
can diamond conduct electricity and why
no
- there are no free delocalised electrons > all used in co bonds
is diamond soluble
no
