unit 4 Flashcards
What is electrolysis?
the process of using electricity to extract elements from a compound
What is the name of the positive electrode?
anode
What is the name of the negative electrode?
cathode
What is an electrolyte?
a 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 electrolysis 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 gas
In the electrolysis of a metal sulfate solution, what is produced at the anode?
oxygen
What is the 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, why is the aluminium oxide mixed with cryolite?
to lower the melting point
In the electrolysis of aluminium oxide, what are the anodes made of?
graphite
