chemical changes

reactivity series

• potassium

• sodium

• lithium

• calcium

• magnesium

• aluminium

• carbon

• zinc

• iron

• hydrogen

• copper

• gold

reactivity series (2)

more reactive metal will displace a less reactive metal

metals less reactive than carbon can be extracted using carbon

acids

H+

alkalis

OH-

neutralisation

H2O

strong acids

completely ionised

weak acids

partially ionised

acid + metal

salt + hydrogen

salt + hydrogen

acid + metal

acid + metal oxide

salt + water

salt + water

acid + metal oxide

acid + metal hydroxide

salt + water

salt + water

acid + metal hydroxide

acid + metal carbonate

salt + water + CO2

salt + water + CO2

acid + metal carbonate

anode

pos electrode

attracting neg ions

cathode

neg electrode

attracting pos ions

electrolysis

H+ and OH- ions present in the electrolyte

at cathode: hydrogen produced unless the metal is less reactive

at anode: oxygen produced unless halide present

if halide is present a halogen is produced

aluminium extraction

aluminium oxide dissolved in molten cryolite

to lower M and B points

saves time, money and energy

graphite anodes shd be replaced regularly bcz they react with O2 to form Co2