MetalsMetals

LearningLearning ObjectivesObjectives

• Use reactivity data to determine a reactivity series

• Relate extraction method to reactivity of metals

• Write word/symbol equations for reduction of metal ores with carbon

Put the metals in order of Put the metals in order of reactivityreactivity

Metal Reaction with dilute

acid

Reaction with water

Reaction with

oxygen

ASome reaction Slow reaction Burns

brightly

B No reaction No reaction Reacts slowly

C No reaction No reaction No reaction

DViolent reaction

Slow reaction Burns brightly

ESlight reaction Reacts with

steam onlyReacts slowly

Displacement reactionsDisplacement reactions

Mg

Magnesium

SO4Cu

Copper sulphate

The magnesium DISPLACES the copper from 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.

The Thermite reactionThe Thermite reaction

Al

Aluminium

Fe OIron oxide

Aluminium DISPLACES iron from iron oxide

Simplified and NOT balanced equation

Pie chart to show the Pie chart to show the elements present in the elements present in the

earth’s crustearth’s crust

Most elements in the Most elements in the earth’s crust are found as earth’s crust are found as

compoundscompoundsCompounds contain atoms of more than 1 element ---------- joined together.There are 2 types of chemical ----IONIC bonds are formed between a metal + non metal. The metal atom TRANSFERS electrons to the non metal.COVALENT bonds are formed between non metals. The atoms SHARE electrons.

Extraction methodsExtraction methodsPotassium

Sodium

Calcium

Magnesium

Aluminium

Carbon

Zinc

Iron

Tin

Lead

Copper

Silver

Gold

Platinum

Metals ABOVE CARBON, because of their high reactivity, are extracted by ELECTROLYSIS

Metals BELOW CARBON are extracted by heating them with carbon in a BLAST FURNACE

These LOW REACTIVITY metals don’t need to be extracted because they are SO unreactive you’ll find them on their own, NATIVE (not in a metal oxide)

N.B. Cu can sometimes be found native

Native metalsNative metals

Unreactive elements (Gold, silver and sometimes copper) do not need to be extracted as they are not chemically combined with any other elements.

Iron

Hematite (iron oxide, Fe2O3)

MagnetiteMagnetite (iron oxide Fe3O4)

• Minerals in rocks are not pure, but mixed with other substances.

• To be useful the metal needs to be extracted from the rock.

• A metal ore is a rock containing enough of the metal compound to make it economic to extract it.

• This can vary over time as demand/ supplies/ value change.

Metal oresMetal ores

The Blast furnaceThe Blast furnace

Reduction with carbonReduction with carbon• Zinc, iron, tin, lead and copper can all be extracted from

their ores by SMELTING.

• Metal ore (OXIDE or SULFIDE) is heated to a high temperature with carbon.

• Carbon DISPLACES the metal.

• This is a REDOX process, the carbon is OXIDISED (gains oxygen) at the same time the metal ore is REDUCED (loses oxygen)

EquationsEquations

From an oxide:

Iron oxide + carbon carbon dioxide + iron(Fe2O3)

2Fe2O3 + 3C 3CO2 + 4Fe

From a sulfide:

Copper sulfide + oxygen sulfur dioxide + copper oxide(CuS)

2CuS + 3O2 2SO2 + 2CuO

Copper oxide + carbon carbon dioxide + copper

(CuO)2CuO + C CO2 + 2Cu

Summary: Summary: Extracting metalsExtracting 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.e anything above

carbon)

Middle reactivity (i.e. anything below

carbon)

Low reactivity