Summer assessment 3 Flashcards
what are ions?
charged particles
What is ionic bonding between?
a metal and non-metal
What is ionic bonding?
oppositely charged ions are strongly attracted to one another by electrostatic attrations
What does ionic bonding form?
giant ionic structure
Describe giant ionic structure?
- ions held together by closely packed 3D lattice arrangement
- strong electrostatic attraction
- high melt + boiling point
- not electrical conductors when solid, only when dissolve in water or melt them
Definition of covalent bond?
strong electrostatic attraction between negatively charged shared electrons and the positively changed nuclei of the atoms involved
Describe simple molecular structures?
- very strong covalent bond
- weak intermolecular forces of attraction between molecules
- low melting and boiling point
Describe giant covalent structures?
- strong covalent bond
- high melting and boiling
- dont conduct electricity
- insoluble in water
Describe diamond?
- network of carbon atoms with four covalent bonds
- strong covalent bonds
- high melting point
- hard rigid lattice structure
- doesnt conduct
Describe graphite?
- each carbon forms three covalent bonds
- layers of carbon atoms with weak intermolecular forces which can slide over each other making it slippery and soft
- high melt and boil
- one delocalised electron and can conduct electricity
Describe C60 fullerene?
- hollow sphere with 60 carbon atoms
- intermolecular foces which can slide over each other - soft
- one delcocalised but cant move molecules so poor conductor
What are alkanes?
saturated hydrocarbons
What are hydrocarbons?
chains of carbon and hydrogen atoms
alkanes general formula?
CnH2n+2
name the first five alkanes?
methane ethane propane butane pentane
WHat do alkanes burn in?
combustion reactions
What does complete combustion of alkane make?
carbon dioxide + water
What can alkanes react with? to form?
halogens to make haloalkanes
what is needed for the substitution reaction?
UV light
Methane + bromine =?
bromomethane + hydrogen bromide
What is electric current?
flow of electrons or ions
What charge do electrons have?
negative
What happens when electrons or ions move?
they cause the material to conduct electricity
When do ionic compounds conduct electricity?
when molten or in a solution ( ions are separate and c an move in the solution)
How are metals held together?
by metallic bonding
Describe metallic bonding?
electrostatic attraction between the positive ions and the electrons
What are metals good conductors of?
electricity and heat
How are most metals malleable?
layers of ions in a metal can slide over each other
percentage yeild?
actual yield/ theoretical yeild x100
concentration?
moles/ volume
volume=?
moles x 24