c6: electrolysis Flashcards
what is the name of the negative electrode
cathode
what is electrolysis
process of using electricity to extract elements from a compound
what is the name of the positive electrode
anode
what is an electrolyte
liquid or solution that contains ions and so can conduct electricity
where are metals formed
cathode
where are non-metals formed
anode
how can ionic substances be electrolysed
by melting or dissolving them, and then passing a direct current through them
why can solid ionic substances not be electrolysed
they do not conduct electricity, or the ions cannot move
in the eletrolysis of solutions, when is the metal not produced at the cathode
when the metal is more reactive than hydrogen
in the electrolysis of a metal halide solution, what is produced at the anode
halogen
in the electrolysis of metal sulfate solution, what is produced at the anode
oxygen
what is the half equation for the ionisation of water
H2O(l) ➞ H+(aq) + OH-(aq)
what metals are extracted from ionic compounds by using electrolysis
metals that are more reactive than carbon
in the electrolysis of aluminium oxide, what are the anodes made of
graphite
in the electrolysis of aluminium oxide, why is the aluminium oxide mixed with cryolite
to lower the melting point
