ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
11.1Oral Presentation (2 groups will be selected for presentation.)
Search the internet (or other resources) for the occurrence of metals and the uses of metals in daily life.
Websites for references:
1)Some common minerals and their uses
2)Minerals and metals for the worlds
Please summarize your classmates’ presentation:
Hand in your summary at the end of the lesson.
ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
11.2Uses related to the properties of metals
Complete the following table:
Metal / Uses / Reasons for usesIron / For construction, building bridges, and the body of vehicles / Hard, strong, malleable and ductile, & cheap
Making magnet / Magnetic
Copper / For making electrical wire, / Excellent conductor of electricity, ductile and corrosion resistant.
water pipes, / Non-poisonous, malleable & ductile, corrosion resistant
and cooking utensils / Excellent conductor of heat, Non-poisonous.
Aluminium / For making overhead power cables, / Very good conductor of electricity, low density, ductile.
aircraft body, / Light but strong, corrosion resistant
saucepans,kitchen foils, / Very good conductor of heat, non-poisonous, corrosion resistant, malleable.
soft drink can, / Non-poisonous, low density, corrosion resistant, and malleable.
& window frames. / Strong, corrosion resistant
Titanium / For making supersonic aircraft / Light but very strong, very corrosion resistant, malleable
Gold / For jewellery, coins, / Attractive golden yellow colour, extremely corrosion resistant, most malleable and ductile
shield for heat, and radiation / Excellent reflective quality
Mercury / For thermometers / Liquid at room temperature, expands on heating
Silver / For jewellery, coins, / Attractive silvery colour, corrosion resistant, malleable and ductile
electrical and electronic components / Good conductor of electricity, ductile and corrosion resistant.
ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
11.3Metal ores
Which metals are found free in the Earth? Why ?
Unreactive metals, such as gold and platinum (at the bottom of the reactivity series), are found free in the Earth’s crust.Metals are usually found in the form of compounds. Which kinds of compounds are found in ores?
Metal oxides, carbonates and sulphides are found in metal ores.Are these metal compounds soluble in water?
They are insoluble in water.Name some common metal ores:
Metal / Name of the main ore / Compound found in ore / Formula of the compoundAluminium / bauxite / Aluminium oxide / Al2O3
Copper / Copper pyrites / Copper iron(II) sulphide / CuFeS2
Iron / Haematite / Iron(III) oxide / Fe2O3
Lead / Galena / Lead(II) sulphide / PbS
11.4Extraction of metals form their ores
What are the three methods for extracting a metal from its ores?
1) Heating the metal ore/oxide alone.2) Heating the metal ore/oxide with carbon/coke.
3) Electrolysis of hot molten ores.
a)Heating the metal ore / oxide alone
What do you observe when zinc oxide is heated?
The white solid turns yellow.What do you see when the hot zinc oxide is allowed to cool?
The yellow solid turns white.ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
Is there any metal formed? No, there isn’t any metal formed.
Which metal oxides give metal when heated?
Merucry(II) oxide and silver oxideWrite chemical equations for the thermal decomposition of
i)mercury(II) oxide : 2HgO(s) 2Hg(l) + O2(g)
ii)silver oxide: 2Ag2O(s) 4Ag(s) + O2(g)
b)Heating metal ore / oxide with carbon
i)lead(II) oxide
What do you see when lead(II) oxide is heated alone?
The yellow solid turns orange.Is there any lead metal formed? No, there isn’t any metal formed.
Heat lead(II) oxide in a charcoal block. (Heat lead(II) oxide with coke.)
What do you see?
Silvery beads of molten lead are formed.Write a chemical equation for the reaction involved.
2PbO(s) + C(s) 2Pb(s) + CO2(g)ii)copper(II) oxide
What do you see when copper(II) oxide is heated alone?
No observable change.Heat copper(II) oxide in a charcoal block. (Heat copper(II) oxide with coke.)
What do you see?
Reddish brown solid copper is formed.Write a chemical equation for the reaction involved.
2CuO(s) + C(s) 2Cu(s) + CO2(g)ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
iii)zinc oxide
Heat zinc oxide in a charcoal block.
What do you see?
The white solid turns yellow.Why?
The hot Bunsen flame does not provide high enough temperature to start the reduction of zinc oxide by carbon.N.B.Which metal is more reactive, lead or zinc? Zinc is more reactive than lead.
Which metal, zinc or lead, forms a more stable oxide? Zinc forms a more stable metal oxide than that of lead.
Bunsen flame is not hot enough to remove oxygen from zinc oxide.
N.B.What is oxidation?
Give examples of oxidation:
Oxidation is the process in which oxygen is added to a substance.What is reduction?
Reduction is the process in which oxygen is removed from a substance.Give examples of reduction:
Lead is formed when lead oxide is heated with carbon.N.B.Name the type of reaction by which metal is extracted from its oxide by heating with carbon.
Reduction of metal oxide by carbon / Redox reaction.
What is the role of carbon in the reaction? Reducing agent.
Reading assignment: Read 11.7 Extraction of iron from haematite in industry (P.244)
ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
iv)galena, lead(II) sulphide
Give the chemical formula of lead(II) sulphide: PbS
How lead is extracted from galena?
Heat (Roast) lead(II) sulphide in air to form lead(II) oxide.Heat lead(II) oxide with carbon to form lead.
Write chemical equations for the reaction involved.
2PbS(s) + 3O2(g) 2PbO(s) + 2SO2(g)2PbO(s) + C(s) 2Pb(s) + CO2(g)
c)Extraction of metals by the electrolysis of its hot molten ores
Which metals are extracted by the electrolysis of molten ores?
Reactive metals (metals that are above zinc in the reactivity series) are extracted by the electrolysis of molten ores.N.B. It is an expensive method.
Examples:Electrolysis of hot molten bauxite,
Electrolysis of molten sodium chloride.
11.5Discovery of metals
Read Table 11.2 (P.237)
What is the relationship between the year of discovery of metals and the relative reactivity of metals?
The more reactive the metal, the more stable is its compounds and the more difficult is it to be extracted. Thus, these metals will a short history and was extracted by Man recently.N.B.Uncreative metals, such as gold and platinum, are found free in nature.
Read Table 11.3 Different Ages in human civilization
(Stone, Copper, Bronze, & Iron Age)
ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
11.6Factors affecting the discovery and use of metals
1)2)
3)
The price of metals depends mainly on:
1)2)
3)
11.7Conserving metals
Why we need to conserve metals?
Ways to conserve metals
1)2)
3)
Importance of recycling:
1)2)
3)
4)
Recycling involves ______, ______, ______, and ______the metal, and ______any unwanted substances. The used metals are then ______and ______into other shapes,
ChemistryClass No.: _____
Chapter 11Occurrenceand extraction of metals
11.8Extraction of iron from haematite in industry (Blast Furnace)
Raw materials: ______
A mixture of ______, ______and ______is added at the top of the furnace. ______air is blown into the furnace from the bottom. A chain of chemical reactions occur:
1)Carbon reacts with oxygen in air to form ______.
Equation: ______
2)The hot carbon dioxide rises in the furnace and is reduced by ______to form ______.
Equation: ______
3)Carbon monoxide is a ______agent. It ______iron(III) oxide in haematite to form hot molten ______.
Equation: ______
The hot molten iron is then rum out from the bottom of the furnace.
4)The formula of limestone: ______
Limestone breaks up ______and ______when heated.
Equation: ______
5)Calcium oxide helps to remove ______(the impurities) to form a liquid ‘______’.
Equation: ______
Chemistry Worksheets / HKCWCC / Chapter 11P. 1