Metals and their extractions Flashcards
What are metals extracted from and where are they found?
Metals are extracted from ores which is a substance found in the Earth’s crust which contains metal compounds.
How can metals be extracted?
Metals can be extracted from their ores by chemical reactions or electrolysis.
What does the reactivity of a metal tell you?
The more reactive a metal is, the more stable its compound is so it’s harder to extract pure metal.
How are metals MORE reactive than carbon extracted?
Electrolysis
How do displacement reactions work?
Any metal can displace a metal lower than itself in the reactivity series from a solution of one of its salts. A displacement reaction is when a more reactive metal displaces a less reactive metal from a compound.
What is reduction?
The removal of oxygen atoms from a chemical or the gain of electrons.
What is oxidation?
The addition of oxygen atoms to a chemical or the loss of electrons.
What does OILRIG stand for?
Oxidation Is the Loss of electrons Reduction Is the Gain of electrons.
What is a redox reaction?
A reaction where both reduction and oxidation occur
What are the raw materials for the extraction of iron and what are they use for?
Iron ore - Source of iron
Coke - Used as a fuel and to produce carbon monoxide for the reduction
Limestone - To remove impurities
Hot air - Provides oxygen so that coke can burn
What is the first step of extracting metals from their ores?
Combustion - The coke burns on the air.
Carbon + Oxygen -> Carbon Dioxide
C + O₂ -> CO₂
What is the second step of extracting metals from their ores?
Oxygen from the hot air reacts with coke (carbon) to form carbon monoxide. This is an exothermic reaction (combustion).
Carbon + Oxygen -> Carbon monoxide
2C + O₂ -> 2CO
What is the third step of extracting metals from their ores?
The carbon monoxide reacts with the iron ore, forming molten iron. This is a reduction reaction.
Iron oxide + Carbon monoxide -> Iron + Carbon Dioxide
Fe₂O₃ + 3CO -> 2fe +3CO₂
What is the fourth step of extracting metals from their ores?
The added limestone thermally decomposes in the heat of the furnace (decomposition).
Calcium carbonate -> Calcium Oxide + Carbon Dioxide
CaCO₃ -> CaO + CO₂
What is the final step of extracting metals from their ores?
The calcium oxide reacts with acidic impurities (silicon dioxide) in a neutralisation reaction.
Calcium oxide + Silicon dioxide -> Calcium silicate (Slag)
CaO + SiO₂ -> CaSiO₃
What are the steps of the extraction of iron?
Combustion - Reduction - Decomposition - Neutralisation
Where is aluminium in the reactivity series?
Aluminium is higher than iron and carbon in the reactivity series.
Why can’t aluminium be extracted like other metals below it in the reactivity series?
So much energy is needed to extract it from its ores and reduction/oxidation reductions involving carbon cannot be used.
How is aluminium extracted?
Aluminium and higher metals in the reactivity series are extracted using electrolysis.
What must be done to aluminium before it’s extracted?
Aluminium oxide is heated to high temperatures making it melt so electricity can pass through it.
What happens when aluminium is extracted?
Positively charged aluminium ions move towards the negatively charged cathode forming aluminium atoms that can be extracted as aluminium metal. Oxygen forms at the positive electrode and it reacts with the carbon forming carbon dioxide which bubbles out of the tank.
What is the negatively charged rod called?
Cathode