Chemistry - 5 Chemical Changes - 5.1 The Reactivity Series & 5.2 Displacement Reactions & 5.3 Extracting Metals

Ore

a rock that contains a large enough concentration of a mineral making it profitable to mine

Oxidation

loss of electrons

Reduction

gain of electrons

Reactivity series

a list of metals which shows them in order of their reactivity, with the most reactive at the top

alkali metal and water

alkali metal + water → metal hydroxide + hydrogen

How can we test for orders of reactivity? [2]

- water (more reactive elements)
- dilute acid (less reactive elements)

Reactivity series:

potassium
sodium
lithium
calcium
magnesium
aluminium
CARBON
zinc
iron
tin
lead
HYDROGEN
copper
silver
gold

Reactivity series mnemonic

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Displacement reaction

a reaction in which a more reactive element displaces a less reactive element from an aqueous solution of the latter's ions.

A more reactive metal will...

displace a less reactive metal from an aqueous solution of one of its salts

Ionic equation

an equation in which ions are explicitly shown

Spectator ion

ion that does not participate in a reaction (not oxidised or reduced)

OILRIG

oxidation is loss, reduction is gain

Half equation

an equation for a redox reaction which considers just one of the species involved and shows explicitly the electrons transferred to or from it.

Redox reaction

an oxidation reaction paired with a reduction reaction

Displacement reactions are also known as...

redox reactions

Oxidising agent

substance that gains electrons

Reducing agent

substance that loses electrons

Where are metals from?

the Earth's crust

Whether it is worth extracting a particular metal depends on [3]:

- how easy it is to extract from its ore
- how much metal the ore contains
- the changing demands for a particular metal

How is copper extracted from copper ores? [5]

- ore is ground up into powder
- mixed with water and chemical that makes copper compound repel water
- air is bubbled through mixture
- copper compound floats to top as froth while rocky bits sink
- concentrated compound is scraped off to be extracted from

How are unreactive metals often found?

in their native state rather than as compounds

metal oxide and carbon

metal oxide + carbon → metal + carbon dioxide

What metals can be reduced using carbon?

metals less reactive than carbon

What metals can be reduced using hydrogen?

metals less reactive than hydrogen

How are metals more reactive than carbon extracted?

electrolysis of the molten metal compound