Electrolysis Extraction Flashcards
What are the electrodes used in electrolysis made out of?
Graphite
Why is graphite the substance electrodes used for electrolysis are made out of?
Because it has free electrons that can move through the graphite
How do metals above CARBON in the reactivity series must be extracted?
Metals above carbon in the reactivity series must be extracted using ELECTROLYSIS
How can metals less reactive than carbon be extracted?
Metals less reactive than carbon can be extracted from their ores by REDUCTION (using carbon, coke, charcoal)
How can platinum, gold and silver be extracted?
Platinum, gold and silver can occur native and do not need to be extracted
How is Aluminium found naturally?
Aluminium is found naturally as the ore aluminium oxide
Why can Aluminium not be extracted by reduction with carbon?
It is too reactive to be extracted by reduction with carbon
Why is the aluminium oxide dissolved in the cryolite?
To lower the melting point
What happens to the oxygen produced in the electrolysis of aluminium oxide?
Oxygen reacts with carbon to make carbon dioxide
Why do the electrodes have to be replaced regularly?
Wears away
Why is extracting aluminium so expensive? (3 points)
- lots of electricity needed
- requires energy
- having to replace electrodes
Why do the ANODES in the electrolysis of aluminium oxide have to be replaced regularly?
- O2 is produced at anode and reacts with the carbon electrode to make carbon dioxide+ wears off
