UNIT 3 - METALS Flashcards
WHAT IS A METAL ORE ?
A metal ore is rock from which metals are obtained
Metals can be extracted using chemical reactions
WHAT IS MEANT BY NATIVE ?
An uncombined metal (gold) nonreactive
As metals become more reactive they become harder to extract
WHAT HAPPENS IN A REDOX REACTION ?
Both reduction and oxidation
In reduction -
Gain of electrons or removal of electrons
In oxidation -
Addition of oxygen or loss of electrons
OIL RIG
WHAT IS A DISPLACEMENT REACTION ?
Used to extract metals from ores
A more reactive metals is used to displace a less reactive metal from a compound
DESCRIBE THE BLAST FURNACE PROCESS
Iron can be extracted by heating it with carbon
The carbon is heated and reacts with oxygen in the air to form CO2
CO2 reacts with more oxygen to form CO
CO is an excellent reducing agent
It reduces the iron oxide into iron and CO2
Limestone breaks down in the heat to form calcium oxide
Calcium oxide reacts with impurities to form slag
Slag is lighter than molten iron so floats to the top where it can be removed
WHAT GOES INTO THE BLAST FURNACE ?
Iron Ore
Coke - Source of carbon / fuel
Limestone
Hot air
WHAT IS CREATED IN THE BLAST FURNACE ?
IRON
SLAG
CO2
WHAT IS THE COMBUSTION REACTION IN THE BLAST FURNACE ?
C = Coke
C + O2 —-> CO2
CO2 + C —–> 2 CO
Coke reacts with oxygen to form CO2
The CO2 reacts with more carbon to form the reducing agent CO
WHAT IS THE REDOX REACTION IN THE BLAST FURNACE ?
Fe2O3 + 3 CO —-> 2 Fe + 3 CO2
Iron is reduced by Co (Lost Oxygen)
CO is oxidised (Gains Oxygen)
WHAT IS THE THERMAL DECOMPOSITION REACTION IN THE BLAST FURNACE ?
CaCo3 ——> CaO + CO2
Limestone breaks down in the heat to form CO2 and calcium oxide
WHAT IS THE NEUTRALISATION REACTION IN THE BLAST FURNACE ?
CaO + SiO2 —–> CaSiO3
Calcium Oxide reacts to silicon dioxide to form slag
WHAT IS ELECTROLYSIS ?
The breaking down of ionic compounds using electricity
WHAT IS AN ELECTROLYTE ?
The molten compound
WHAT HAPPENS IN ELECTROLYSIS ?
The ions in the molten metal compound are free to move
positive Pb 2+ ions are attracted to the negative cathode where they gain electrons and are reduced to form lead
Negative Br- ions are attracted to the positive anode where they lose electrons and are oxidised to form bromine
WHAT KIND OF POWER SUPPLY IS USED IN ELECTROLYSIS ?
D.C.