Note:

IGCSE Chemistry Topic Questions Paper 4 Extended Theory on Metals

The following concepts will be tested in this examination:

10.1 Properties of metals

Core 

• List the general physical properties of metals 
• Describe the general chemical properties of metals, e.g. reaction with dilute acids and reaction with oxygen 
• Explain in terms of their properties why alloys are used instead of pure metals 
• Identify representations of alloys from diagrams of structure

10.2 Reactivity series

Core 

• Place in order of reactivity: potassium, sodium, calcium, magnesium, zinc, iron, (hydrogen) and copper, by reference to the reactions, if any, of the metals with: – water or steam – dilute hydrochloric acid and the reduction of their oxides with carbon
• Deduce an order of reactivity from a given set of experimental results

Supplement 

• Describe the reactivity series as related to the tendency of a metal to form its positive ion, illustrated by its reaction, if any, with: – the aqueous ions – the oxides of the other listed metals 
• Describe and explain the action of heat on the hydroxides, carbonates and nitrates of the listed metals 
• Account for the apparent unreactivity of aluminium in terms of the oxide layer which adheres to the metal

10.3 Extraction of metals

Core 

• Describe the ease in obtaining metals from their ores by relating the elements to the reactivity series 
• Describe and state the essential reactions in the extraction of iron from hematite 
• Describe the conversion of iron into steel using basic oxides and oxygen 
• Know that aluminium is extracted from the ore bauxite by electrolysis 
• Discuss the advantages and disadvantages of recycling metals, limited to iron/steel and aluminium

Supplement 

• Describe in outline, the extraction of zinc from zinc blende 
• Describe in outline, the extraction of aluminium from bauxite including the role of cryolite and the reactions at the electrodes

10.4 Uses of metals

Core 

• Name the uses of aluminium: – in the manufacture of aircraft because of its strength and low density – in food containers because of its resistance to corrosion 
• Name the uses of copper related to its properties (electrical wiring and in cooking utensils)
• Name the uses of mild steel (car bodies and machinery) and stainless steel (chemical plant and cutlery)

Supplement

• Explain the uses of zinc for galvanising and for making brass
• Describe the idea of changing the properties of iron by the controlled use of additives to form steel alloys