52-55 - Extracting Metals Flashcards
What is an ore?
A rock containing enough metal to make its extraction economical
Why is gold found in the earth?
It’s not very reactive
How might the profitability of metal extraction change?
The price for a metal could rise or drop
Technology could make extraction cheaper
What are the two ways of extracting metals from ores?
Reduction
Electrolysis
What is reduction?
When carbon replaces the oxygen in a metal oxide
How is iron oxide extracted?
Reduced with carbon in a blast furnace
Why do some metals have to be extracted with electrolysis?
More reactive than carbon
What are the issues with electrolysis?
Expensive because of the energy it takes
Transport of waste rock is expensive
Why does copper need to go through electrolysis?
It is impure after reduction and doesn’t conduct electricity
What is an electrolyte?
A liquid that conducts electricity
Often a metal salt solution
What is the charge of an anode?
Positive
What is the charge of a cathode?
Negative
What are the steps of electrolysis?
Anode pulls copper atoms into solution to form Cu2+ ions
These ions gain electrons at the cathode, become copper atoms
Impurities form a sludge by the anode
What is the cathode in electrolysis?
A thin piece of pure copper
What is the anode in electrolysis?
A lump of impure copper which dissolves
