Extracting Metals Paper 1 Flashcards
Metal + water —->
Metal hydroxide + hydrogen.
Metal + acid ——>
Salt + hydrogen.
The reactivity series:
Potassium Sodium Calcium Magnesium Aluminium (CARBON) Zinc Iron (HYDROGEN) Copper Silver Gold
What happens in a metal displacement reaction?
A more reactive metal will displace a less reactive metal from its salt in water.
If you put Mg into copper sulphate(aq)?
A displacement reaction would occur and it would form magnesium sulphate + copper in the beaker.
Atoms are ___________ when they form cations?
Oxidised.
What’s the half equation for oxidation of Mg?
Mg —> Mg(2+) + 2e-
What is an ore?
An ore is a rock which contains enough metal to make its extraction economical.
How can we purify copper oxide?
By heating and reacting it with hydrogen. To make CU + H20
Metals high up in the reactivity series corrode easier in air. What is the execution of this rule?
Aluminium is protected by a oxide layer so goes against this rule.
What 2 things effect what method is used to extract metal from its ore?
- cost of the extraction process (economic factor)
- the metals position in the reactivity series.(chemical factor)
How is iron extracted?
Iron is less reactive than carbon so its produced by reducing iron oxide by reacting it with carbon. Inside a blast furnace.
Iron oxide + carbon —> iron + carbon monoxide.
This creates pure molten iron.
How Is aluminium extracted?
As aluminium is more reactive than carbon, the aluminium is reduced in a electrolytic cell. The aluminium is dissolved in cryolite to reduce the temp. Then electrolysis takes place. Al+ goes to the cathode and O(2-) goes to the anode.
What are 3 biological metal extraction methods?
- using scrap iron.
- phytoextraction
- bioleaching.
A high grade of ore means that …
There is a good proportion of rock : metal compound.
A low grade of ore means that there is …
A bad rock to metal compound ratio.
Low grade ore is … (compared to high grade ores)
- more common as high grades have already been used.
- less profitable
- uses more energy
- produces more waste.
How do we use some scrap iron?
To make copper as we are more in need of that. So they carry out a displacement reaction of:
Iron + copper sulphate —> iron sulphate + copper.
What is phytoextraction?
It’s a biological way to extract metal out of plants. In plants metal compounds get absorbed by the roots, plants concentrates these compounds in the leaves and stem. The plant gets burned. The ash contains metal compounds to use.
What is bioleaching?
It’s a biological method of metal extraction using bacteria. Copper can be extracted from copper sulphate by:
Bacteria oxidise sulphide ions. The copper sulphide ores break down, and pure copper cations are released.
Why recycle metal?
It has economic implications as well as helping to preserve the environment and supply of limited resources.
Why not extract metals instead of recycling?
- uses up limited resources.
- uses a lot of energy
- damages the environment.
Why recycle metal?
- metal ores will last longer.
- less energy is needed.
- fewer quarries and mines are needed.
- less noise and dust produced.
- less land needed.
What are the drawbacks of recycling?
- used metal items must be collected and transported to the recycling centre.
- different metals must be removed from original items.
- recycling only saves energy depending on the metal involved.
