Extracting Metals Flashcards
why are most metals only found as compounds?
because the metal has reacted with other elements in the past
what are metals extracted from
metals are extracted from Ores
how can metals less reactive than carbon be extracted
can be extracted from their oxides (compounds with oxygen) by reducing with carbon.
why is carbon used
as its cheap and comes in abundance
what happens in the reduction
the metal oxide loses oxygen to form a pure metal
NOTE:
Reduction with carbon normally involves heating the metal oxide in the presence of the carbon, which is often used in the form of coal.
NOTE:
Reduction with carbon normally involves heating the metal oxide in the presence of the carbon, which is often used in the form of coal.
what is the formula for aluminium ore
AL203
when is electrolysis used
Electrolysis is used to extract reactive metals from molten ores
what are molten ores
melted materials containing metals
NOTE: explain the electrolysis process in regard to AL203:
Powdered aluminium ore (Al2O3) is first mixed with another aluminium salt called cryolite.
This mixture has a lower melting point than pure Al2O3. This makes it cheaper as less energy is needed to melt the powder.
Once molten, a large voltage is applied.
NOTE: explain the electrolysis process in regard to AL203:
Powdered aluminium ore (Al2O3) is first mixed with another aluminium salt called cryolite.
This mixture has a lower melting point than pure Al2O3. This makes it cheaper as less energy is needed to melt the powder.
Once molten, a large voltage is applied.
what is formed at the cathode ( AL203 )
Cathode - Aluminium
what is formed at the anode ( AL203 )
Anode - Carbon Dioxide
what is the anode usually made up off
Carbon as it’s a good conductor and is cheap
What is a disadvantage of using electrolysis to extract reactive metals?
A lot of energy is needed.
- to melt the solid ionic compound to allow the ions to flow
- to produce the electrical current
All this energy costs a lot of Money
Which element is used for extracting metals from their compounds by reduction?
Carbon
