Chemistry - Extraction of Metals

Zinc is mixed with copper to make an alloy brass, why is brass harder than pure copper?

* ions of pure copper are the same size.
* these layers of ions easily slide over each other.
* ions of zinc and copper are different sizes.
* this disrupts the layers / the structure of copper.
* this makes it more difficult for layers to slide over each other.

How are unreactive metals found?

Chemically uncombined

Why is an alloy harder than pure metal?

alloys contain different sizes which distorts the regular arrangement of atoms.

this makes it more difficult for layers to slide over each other.

Definition of an alloy:

a mixture of 2 or more elements with at least one being a metal.

Uses of copper:

Electrical wires : very good conductors of electricity + ductile.

Pots & pans : very good conductor, unreactive + malleable.

Water pipes : unreactive + malleable.

Surfaces in hospitals : antimicrobial properties + malleable.

Extracting metals below carbon:

Displacement :

e.g. copper oxide + carbon —> copper + carbon dioxide

* get carbon from coal ( coal = cheap + there’s plenty present)

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( copper expide = lost oxygen = reduced = carbon = gained oxygen = oxidised)

Why can carbon be used to extract copper from copper oxide?

Carbon is more reactive than copper so carbon is able to displace copper from copper oxide.

Where are most metals extracted from?

The earths crust