2.3 Metals & Their Extraction Flashcards
What are ores
Minerals found in the Earth’s crust
Contain metal compounds, from which metals can be extracted using chemical reactions
What does the method used to extract metals from their ores depend on?
The metal’s position in the reactivity series
Give 2 metals that are found native - what does this mean
Gold and silver - they don’t need to be extracted
What does the difficulty of extracting methods increase with
Reactivity
How are the most reactive metals extracted from their ores
Electrolysis
How are the metals in the middle of the reactivity series extracted from their ores
They are chemically reduced
How can the relative reactivity of metals be demonstrated
Displacement reactions
What happens in displacement reactions
A more reactive metal will displace a less reactive metal from a solution of one of its salts
Displacement reaction example
iron + copper(II)chloride –> iron chloride + copper
copper has been displaced by iron :( (now its alone)
What happens in a competition reaction
A more reactive metal removes oxygen from the oxide of a less reactive metal when a mixture of the 2 is heated
Example of a competition reaction
The thermit reaction
Thermit reaction equation
iron(III) oxide + aluminium –> iron + aluminium oxide
Thermit reaction used for?
USed to weld rails together on a railway track
What is oxidation
The gain of oxygen
The loss of electrons (OILRIG)
What is reduction
The loss of oxygen
The gain of electrons (OILRIG)
What are the raw materials used in the blast furnace (4)
- iron ore - source of iron
- coke - as a fuel & to produce carbon monoxide for the reduction
- limestone - to remove impurities by forming slag
- hot air - provides oxygen so coke can burn
What type of reaction is the production of iron in the blast furnace
Reduction
First step in the production of iron - blast furnace
Endothermic or exothermic
Oxygen from the hot air reacts with carbon (coke) to form carbon monoxide
Exothermic which heats the surface
Second step in the production of iron
What’s reduced?
Carbon dioxide then reacts with iron (III) oxide (from iron ore) to give iron
iron is reduced!
3rd step in the production of iron - blast furnace
Limestone deposits thermally to form calcium oxide
4th step in the production of iron - blast furnace
Calcium dioxide reacts with silicon dioxide (sand) to from slag; This is removed
Chemical equation of 1st step in production of iron
Oxygen from the hot air reacts with carbon (coke) to form carbon monoxide
2C + O2 –> 2CO
Chemical equation of 2nd step in production of iron
Carbon dioxide then reacts with iron (III) oxide (from iron ore) to give iron
iron is reduced!
Fe2O3 + 3CO –> 2Fe + 3CO2
Chemical equation of 3rd step in production of iron
Limestone deposits thermally to form calcium oxide
CaCO3 –> CaO + CO2
Chemical equation of 4th step in production of iron
Calcium dioxide reacts with silicon dioxide (sand) to from slag
CaO + SiO2 –> CaSiO3
What type of reaction is the production of iron in a blast furnace
Neutralisation as CaO is basic, silica is acid
Why is the production of iron in the blast furnace continuous
New raw materials are added and products remove all the time (due to the cost of getting the furnace hot enough)
Electrolysis defintion
The process of breaking down an ionic compound using electrical energy