EXTRACTION AND USES OF METALS Flashcards
most metals are extracted from
the earths crust
unreactive metals are found
in the earths crust as an uncombined element
reactive metals are found
in the earths crust combined with other metals
the tendency to be oxidised is linked to
how reactive a metal is
what metals are less resistant to oxidation
reactive metals
extraction of metals is determined by thier
position in the reactivity series
most reactive metals are extracted by
electrolysis of molten chloride or oxide
is electrolysis expensive and why
yes because large amounts of electricity are needed
what metals are extracted by electrolysis (6)
potassium
sodium
lithium
calcium
magnesium
aluminium
how are lesser reactive metals extracted
by heating with a reducing agent like carbon or carbon monoxide
what metals are extracted by heating with a reducing agent (3)
zinc
iron
copper
is heating by using a reducing agent expensive and why
NO
as carbon is cheap and can be a source of heat
silver and gold are extracted as
pure elements
extraction of a metal from its ore involves
removing oxygen from metal oxides
If the ore contains a metal which is below carbon in the reactivity series then the metal is extracted by
reaction with carbon in a displacement reaction.
The raw material iron core or hematite is used as a source of what metal
iron
coke is used to
provide carbon
limestone is used for
neutralising acidic impurities
uses of aluminium (4)
aircraft bodies
saucepans
overhead electrical cables
food cans
why is aluminium used for food cans
it is non toxic, and resistant to corrosion and acidic food stuffs
why is aluminium used for electrical cables
very good conductor of electricity
why is aluminium used for saucepans
very good conductor of heat and unreactive
uses of copper (3)
electrical wiring
saucepans
water pipes
why is copper used for electrical wiring
ductile and very good conductor of electricity
why is copper used for saucepans
very good conductor of heat, unreactive metal
why is copper used for water pipes
doesn’t react with water - non toxic and malleable
uses of iron (2)
building material
catalyst
why is iron used for building material
Good strength, malleable and ductile, relatively inexpensive
why is iron used as a catalyst
Increases the rate of reaction without being used up
3 types of steel
mild
high carbon
stainless
what is mild steel used for and why
Car body panels and wiring
beacuse its malleable and soft
what is high carbon steel used for and why
tools because its hard
what is stainles steel used for and why
cutlery, sinks, chemical plants because its Strong and resistant to corrosion
what is an alloy
a mixture of 2 or more metals or a metal and a non metal
alloy properties
- harder and stronger
- more resistant to corrosion
why are alloys more useful than pure metals
because their properties are enhanced ( will be harder and less prone to corrosion)
are alloys mixtures or compounds
mixtures
what happens if a force is applied to a pure metal
the layers can slide over each other meaning the metal is malleable and ductile
in metals, the atoms are all ___ size
equal
in alloys, the atoms are all ___ sizes
different
what does it mean that the atoms are different sizes in alloys
it distorts the regular arrangement of atoms the metal so it is harder for the layer to slide over one another
so talking about atom sizes why are alloys better to use than metals
as the atoms are all different sizes, it distorts the regular arrangement of atoms the metal so it is harder for the layer to slide over one another
