C1.4 Obtaining and Using Metals Flashcards
What is the term used for getting a metal ore out of the ground?
Extraction.
What is a metal ore?
A metal compound that is found naturally in the earths crust.
What reaction separates a metal from its ore?
A reduction reactions, which is where oxygen is lost.
What metals can be extracted through heating with carbon?
Metals that are less reactive than carbon eg. Zinc, Iron, Tin, Lead.
How does heating with carbon extract a metal from its ore?
The carbon takes the oxygen from the ore.
How are metals extracted from the ore if they are more reactive than carbon?
Through electrolysis.
What is an example of a reduction reaction to extract a metal from its ore?
Iron oxide + Carbon -> Iron + Carbon dioxide
What is the main aluminium ore?
Bauxite, which contains Al2O3.
What happens during the electrolysis of molten aluminium oxide?
The aluminium oxide decomposes into oxygen and aluminium atoms. The aluminium atoms sink to the bottom.
Why is heating with carbon the preferred method of metal extraction?
Electrolysis is very expensive, and heating with carbon is much cheaper.
What are some of the basic common properties of metals?
They are:
Strong
Malleable
Good conductors of heat and electricity.
What are some common uses of metals?
Making:
Bridges and and cars due to their ‘bendability’
Saucepans due to their ability to conduct heat
Wires due to their ability to conduct electricity.
What are some of the properties and uses of aluminium?
Properties: Low density, corrosion resistant and forms strong alloys.
Uses: A structural material in window frames, electricity cables and aircraft.
What are some of the properties and uses of copper?
Properties: Hard, Strong, high melting point, good conductor.
Uses: Wires, pipes.
What is corrosion in metals?
When the metal reacts with oxygen and water to form a hydrated oxide?
What is rust?
Hydrated iron oxide.
Why is pure iron not very useful?
It is too bendy.
Why is pure iron too bendy?
The rows of atoms slide over each other as it has a regular arrangement of atoms.
How is iron made stronger?
It is changed into an alloy called steel. This is made by mixing it with carbon.
What is low carbon (0.5%) steel used for?
Car bodies, because it is easily shaped.
What is high carbon (1.5%) steel used for?
Blades for cutting tools and bridges because it is very hard.
How is stainless steel made and what is it used for?
It is made by adding chromium or nickel to iron and is used in cutlery and containers for corrosive substances because it is rust-resistant.
Why are gold alloys used in jewellery rather than pure gold?
Pure gold is too soft so metals like zinc, copper and nickel are added.
What is ‘shape memory’ in an alloy?
The ability to return to its original shape.
Why is it important to recycle metals?
It takes less: Resources Energy Money Rubbish
What are some of the benefits to recycling aluminium?
You save (per kg of recycled aluminium) :
95% energy
4kg of ore
A lot of waste.
