C6 - electrolysis Flashcards
what is an electrolyte
the compound that is broken down by electrolysis
what is the anode
the positive electrode
what is the cathode
the negative electrode
what happens to POSITIVELY charged ions during electrolysis
they move to the cathode
what happens to NEGATIVELY charged ions during electrolysis
they move to the anode
why can ionic compounds only be electrolysed when they are molten/dissolved in water
because their ions are free to move around and carry their charge to the electrode
what is the order of discharge at the anode (starting at the easiest)
halide ion
hydroxide
all other negatively charged ions
does reduction or oxidation occur at the cathode
reduction
does reduction or oxidation occur at the anode
oxidation
what happens at the anode
oxygen gas is given off
halogen is produced is the electrolyte is a halide
which ore do you get aluminium oxide from
bauxite
how do you electrolyse aluminium oxide
mix it with molten cryolite to decrease the melting point
where does aluminium form
the cathode
what is the half equation for the reaction of aluminium at the cathode
Al(3+) + 3e- -> Al
what is the half equation for the reactive of oxygen at the anode (during electrolysis of aluminium)
2O(2-) -> O2 + 4e-
