getting metals from rocks Flashcards
1
Q
what is a metal ore?
A
a rock which contains enough metal worth extracting
2
Q
how are metals removed from ores?
A
chemical reactions,reduction and electrolysis
3
Q
what is reduction?
A
removing the oxygen from ore
4
Q
which metals can be extracted by electrolysis?
A
the more reactive metals. e.g. potassium,sodium,calcium,magnesium and aluminium
5
Q
what metals can be extracted by reduction and carbon?
A
the less reactive metals e.g. zinc,iron,tin and copper
6
Q
how does electrolysis work?
A
- the ore is heated in a furnace,this is called smelting
- copper produced this way is impure,so it isn’t very useful
- electrolysis is used to purify it,it’s very expensive though
- this makes the copper very pure and useful
7
Q
what is electrolysis?
A
- electrolysis is the breaking down of substances using electricity
- it requires a liquid to conduct the electricity(called the electrolyte)
- electrolytes are often metal salt solutions or molten metal oxides
- the electrolyte has free ions-these conduct electricity
- electrons are taken away by the (positive)anode and given away by the (negative)cathode.
as ions gain or lose electrons they become atoms or molecules and are released
8
Q
how does electrolysis get copper?
A
- electrons are pulled off copper atoms at the anode,causing them to go into solutions as Cu2+ ions.
- Cu2+ ions near the cathode gain electrons and turn back into copper atoms
- the impurities are dropped at the anode as a sludge,whilst pure copper atoms bond to the cathode
9
Q
how does displacement reactions to extract copper?
A
- more reactive metals react more vigorously than less reactive metals
- if you put a reactive metal into a solution of a dissolved metal compound, the reactive metal will replace the less reactive metal in the compound
- this is because the more reactive metals bond more strongly to the non metal bit of the compound and pushes out the less reactive metal
10
Q
where is gold found?
A
in rocks,because it is a unreactive metal
