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Reactivity of Metals

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Reactions of metals with oxygen

When a metal reacts with oxygen it will form a METALOXIDE. This is what happens when a metal rusts. We canmake this reaction happen quicker by burning the metal.

METAL + OXYGEN METAL OXIDE

Copy and complete the following reactions:

1) Magnesium + oxygen2) Copper + oxygen

3) Calcium + oxygen

4) Iron + oxygen

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Reactions of metals with water

When a metal reacts with water hydrogen is always given

off. The other product will be either a metal hydroxide ora metal oxide.

Copy and complete the following reactions:

1) Sodium + water2) Potassium + water

3) Calcium + water

4) Iron + steam

METAL + WATER METAL OXIDE + HYDROGEN

METAL + WATER METAL HYDROXIDE + HYDROGEN

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Reactions of metals with acidsWhen a metal reacts with an acid it gives off hydrogen

(which can be popped using a lit splint). The otherproduct is a salt.

Copy and complete the following reactions:

1) Calcium + hydrochloric acid2) Zinc + hydrochloric acid

3) Iron + hydrochloric acid

4) Lithium + sulphuric acid

METAL + ACID SALT+ HYDROGEN

e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen

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Complete the following reactions:

1) Lithium + water2) Lithium + hydrochloric acid

3) Silver + oxygen

4) Magnesium + sulphuric acid

5) Potassium + oxygen

6) Aluminium + oxygen

7) Manganese + water

8) Sodium + sulphuric acid9) Lithium + oxygen

10) Nickel + hydrochloric acid

Lithium hydroxide + hydrogenLithium chloride + hydrogen

Silver oxide

Magnesium sulphate + hydrogen

Potassium oxide

Aluminium oxide

Manganese oxide + hydrogen

Sodium sulphate + hydrogenLithium oxide

Nickel chloride + hydrogen

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An example question on reactivity

Metal Reaction withdilute acid Reactionwith water Reactionwith oxygen

ASome reaction Slow reaction Burns brightly

B No reaction No reaction Reacts slowly

CNo reaction No reaction No reaction

DViolent reaction Slow reaction Burns brightly

EReasonablereaction

Reacts withsteam only

Reacts slowly

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The Reactivity Series

The Reactivity Series listsmetals in order of reactivity:

Potassium

Sodium

Calcium

Magnesium

AluminiumCarbon

Zinc

Iron

Lead

Copper

Silver

Gold

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27/04/2012Displacement reactions

Mg

Magnesium

SO4Cu

Copper sulphate

The magnesiumDISPLACES the copperfrom copper sulphate

SO4Mg

Magnesium sulphate

Cu

Copper

A displacement reaction is one where a MORE REACTIVE metal will

DISPLACE a LESS REACTIVE metal from a compound.

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Displacement reactions

A displacement reaction is one where a MORE REACTIVEmetal will DISPLACE a LESS REACTIVE metal from acompound.

For example, if you drop some magnesium into coppersulphate a reaction will happen because magnesium is morereactive than copper, so the reaction is:

Magnesium + copper sulphate copper + magnesium sulphate

However, if you drop some copper into magnesium sulphate

NOTHING will happen.

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Some example reactions

Reaction Prediction Observations

Zinc + copper sulphate

Zinc + lead nitrate

Copper + lead nitrate

Copper + silver nitrate

Extension workwrite down the equations for these

reactions

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Some example reactions

Reaction Prediction Observations

Zinc + copper sulphate Reaction DID happen

Zinc + lead nitrate Reaction DID happen

Copper + lead nitrate Reaction DID NOThappen

Copper + silver nitrate Reaction DID happen

Extension workwrite down the equations for these

reactions

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Extracting Metals

Some definitions:

A METAL ORE is a mineral or mixture of minerals fromwhich it is economically practical to extract somemetal.

Most ores contain METAL OXIDES (e.g. rust = iron

oxide).

To extract a metal from a metal oxide we need to

REDUCE the oxygen. This is called a REDUCTIONreaction.

2 /04/2012H d d ?

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27/04/2012How do we do it?Potassium

Sodium

Calcium

Magnesium

Aluminium

Carbon

Zinc

Iron

Tin

LeadCopper

Silver

Gold

Platinum

Metals ABOVE CARBON, becauseof their high reactivity, areextracted by ELECTROLYSIS

Metals BELOW CARBON areextracted by heating them withcarbon in a BLAST FURNACE

These LOW REACTIVITY metalsblatantly wont need to be extractedbecause they are SO unreactive youllfind them on their own, not in a metal

oxide

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Extracting metals

1) What is an ore?

2) In what form are metals usually found in the Earth?

3) How do you get a metal out of a metal oxide?

4) What is this type of reaction called?

Type of metal Extraction process Examples

High reactivity (i.eanything above carbon)

Middle reactivity (i.e.anything below carbon)

Low reactivity

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The Blast Furnace1) HAEMATITE (iron ore),

limestone and coke (carbon) arefed in here

2) Hot air isblasted in

here

3) The carbon reacts with

oxygen from the air to formcarbon dioxide.

4) The carbon dioxide reactswith more carbon to formcarbon monoxide

6) Molten slag(waste) istapped off here

5) Carbon monoxide reducesiron oxide to iron. Themolten iron is tapped off here

Iron oxide + carbon monoxide iron + carbon dioxide

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Electrolysis

Molecule of solidcopper chloride

Molecule of solidcopper chloride afterbeing dissolved

Chloride

ion

Copper

ion

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ElectrolysisElectrolysis is used to extract a HIGHLY REACTIVE metal.

= chloride ion

= copper ion

When we electrolysedcopper chloride the

negative chloride ions

moved to the positiveelectrode and the positivecopper ions moved to the

negative electrodeOPPOSITES ATTRACT!!!

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27/04/2012Redox reactionsThese happen during electrolysis:

These two processes arecalled REDOX REACTIONS

OILRIG Oxidation Is Loss of electrons

Reduction Is Gain of electrons

At the positive electrode thenegative ions LOSE electrons tobecome neutral this is

OXIDATION

At the negative electrode thepositive ions GAIN electrons tobecome neutral this is

REDUCTION

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Purifying

Aluminium

Aluminium has to be extracted from its ore (called ________) byelectrolysis. This is because aluminium is very ___________. The oreis mixed with cryolite to lower its ________ ________. The ore isthen melted so that the ions can ______. The positively chargedaluminium ions gather at the ___________ electrode. Oxygen formsat the positive electrode and causes it to wear away, which means thatthey have to be __________ frequently.

Wordsmelting point, replaced, negative, bauxite, reactive, move

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Rusting Experiment

RUST NO RUSTno water

NO RUSTno oxygen

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27/04/2012RustingRust is formed when iron reacts with water AND oxygen.

Its an example of an oxidation reaction which can besped up using salt. There are several ways of dealingwith rust:

1) Regular painting or oiling

2) Galvanising this is when iron objects are coated withzinc

3) Making objects out of a non-rusting metal, such asstainless steel

4) Attaching zinc bars to ships the water will reactwith the zinc before it reacts with the iron, becausezinc is more reactive