Chapter 14.1, 14.4, 14.5 Extraction of metals, Alloys, etc Flashcards
What is the most abundant meatal in the earth’s crust
Aluminium
What are ores
The rocks which we obtain the metals from
What is Hematite
iron ore - Fe2O3
What is Bauxite
Aluminium ore - Aluminium Oxide
In what form is gold found and why
Gold is found in its elemental form because it is urneactive
What is silica
Silicon (IV) oxide
General process of extracting metal from ore
Metal compound –(reduction)—> metal
Extraction of metals reactivity series
What Extraction method is used
Electrolysis:
Potassium
Sodium
Calcium
Magnesium
Aluminium
—————
electrolysis can be used as these metals are more reactive than carbon
—————-
Carbon
—————-
Heating in a furnace with carbon or carbon monoxide:
—————-
Zinc
Iron
Copper
—————-
Found naturally as elements:
Silver
Gold
Trends in the extraction series
Down to up:
reactivity increases
Ores harder to decompose
More Powerful extraction is required
Method of extraction is more expensive
Why isn’t electrolysis used for all
Expensive since a large amount of electricity is required
What is aluminum used for and why
Overhead electricity cables - Good conductor of electricity, light, ductile, corrosion resistant
Cooking foil, food containers, drink cans - Light, non-toxic, resists heat and corrosion, malleable
Aircraft - low density
What is copper used for and why
Electrical wiring - ductile, good conductor of electricity
What is zinc used for and why
Coating or galvanizing iron and steel - Prevents rusting through sacrificial protection, keeps air and moisture out
Torch batteries - gives a current when connected to a carbon electrode.
What are alloys
Mixture of a metal with at least one other element
Why are alloys made
To change the properties of the original metal, making it more useful
Why do alloys have different properties from the original element
A pure metal has a lattice of positive ions that can slide over each other and a sea of electrons around it.
But when an alloy is made, the new element’s atoms enter the lattice, which makes it harder for them to slide over each other. Therefore new alloy is harder and stronger
What are all the properties the alloy differs from compared to the original
Strength
Resistance to corrosion
Ability to conduct electricity and heat
The melting point
The appearance
(doesn’t have to change all 5, can change however many)
Describe brass
what its made of
Special properties (name 2)
Uses (name 2)
Copper + Zinc
Special properties:
Harder than copper, easy to shape (malleable), looks attractive, doesn’t corrode
Uses:
Musical instruments, ornaments, door knobs
Describe a typical stainless steel
what its made of
Special properties (name 2)
Uses (name 2)
Iron + Chromium, Nickel, Carbon, (more)
Special properties:
Strong, Resists corrosion, looks attractive
Uses:
cutlery, cooking utensils, construction, equipment in hospitals and factories