c1.2 limestone
DESCRIPTION
TRANSCRIPT
C1.2 Limestone & building materials
Rocks provide essential building materials. Limestone is a naturally occurring resource that provides a starting point for the manufacture of cement and concrete.
Summary
In this section you should be able to:
• know that limestone is needed for buildings and that the positive benefits of using this material should be considered against the negative aspects of quarrying.
• consider and evaluate the environmental, social and economic effects of exploiting limestone and producing building materials from it.
• evaluate the developments in using limestone, cement and concrete as building materials, and their advantages and disadvantages over other materials.
LimestoneDecomposeThermal decompositionSaltCementConcreteMortar
Chemical compoundsCalcium carbonate CaCO3
Calcium oxide CaOCarbon dioxide CO2
Calcium hydroxide Ca(OH)3
LimewaterCarbonates
Key words
What do these things have in common?
They are all mainly Calcium Carbonate!
CaCO3
Heating limestone
You will need:• PPE (lab coat and
goggles)• Bunsen• Tripod• Crucible• Pipe clay triangle• Test tube rack• Large test tube• Distilled water
Limestone cycle Chemical names
Calcium carbonate
Heat Carbon dioxide
CalciumOxide
Carbon dioxide
CalciumHydroxide (aq)
CalciumHydroxide
WaterWater
Limestone cycle Chemical formula
CaCO3
HeatCO2
CaO
Ca(OH)2
WaterWater
CO2
Ca(OH)2 (aq)
Limestone cycle Common names
Limestone HeatCO2
Quick limeLime water
Slaked lime
WaterWater
CO2
Limestone Chemical formula:
Include name, formula and nickname
Heating produces
Adding water produces
Include name, formula and nickname
The proper name for this process is
The same thing happens with other carbonates like
This rock is extracted by Problems caused by extraction
Benefits of extraction
This can be used for…
This is called…..
It is useful for…
Solution in water
Carbonates react with acid to form
Cement, mortar and concrete
Can be caused by the environmental problem of
Heating limestone with clay produces…
This is mixed with sand to make…
Or with sand and aggregate (gravel + crushed stone) to make…
Limestone Chemical formula:
CaCO3
Include name, formula and nicknameQuicklime Calcium oxideCaO
Heating produces
Adding water produces
Include name, formula and nicknameSlaked limeCalcium hydroxideCa(OH)2
The proper name for this process isThermal decomposition
The same thing happens with other carbonates like magnesium carbonate, zinc carbonate
This rock is extracted by
quarryingProblems caused by extractionLorries – causing dust and pollution in rural areasDust Damages natural beauty of area
Benefits of extraction Job creationLimestone has uses in construction and in industry e.g. manufacture toothpaste and cosmetics
This can be used for…Neutralising acid soils
Calcium hydroxide dissolved in water is called limewater
It is useful as a test for the presence of CO2 (goes cloudy)
Solution in water
Carbonates react with acid to form a salt (e.g. calcium chloride), CO2 and H2O
Cement, mortar and concrete
Can be caused by the environmental problem of acid rain
Heating limestone with clay produces…cement
This is mixed with sand to make…mortar
Or with sand and aggregate (gravel + crushed stone) to make… concrete
Q1. Limestone has been called the Earth’s most useful rock.(a) Limestone contains calcium carbonate, CaCO3.
(i) Complete the table to show the number of atoms of each element in the formula of calcium carbonate. Calcium has been done for you.
Element Number of atoms in the formula CaCO3
Calcium, Ca 1
Carbon, C
Oxygen, O
(ii) The diagram below represents a carbon atom. Use words from the box to label the parts of this atom. bond electron molecule nucleus
(b) At a cement works, limestone is mixed with clay and heated in a kiln.
Use the information in the diagram to answer these questions.(i) Name the fuel that is used to heat the limestone and clay......................................................................................................................
(ii) Limestone contains calcium carbonate, CaCO3.
Draw a ring around the correct gas in the box to complete the sentence.
The gas formed when calcium carbonate decomposes is
argon.
carbon dioxide.
nitrogen.
(c) The cement works starts to burn a different fuel.
Local residents are concerned because more children are suffering asthma attacks. Residents have also noticed that parked cars are becoming dirty because of smoke particles from the chimney.
The table shows the possible medical risk from smoke particles.
Particle size in mm Medical effect
Larger than 0.4 No medical risks known
0.3 and smaller Causes asthma attacks
0.2 and smaller May cause cancer
(i) Give two reasons why local residents are concerned about the cement works burning a different fuel.
1 ........................................................................................................................
...........................................................................................................................
2 ........................................................................................................................
........................................................................................................................... (2)
(ii) The company operating the cement works stated that smoke particles from the chimney had not changed since it started burning the different fuel.
If you were a local resident, what evidence would you like to see to help you decide if the company’s statement is true or not?
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(2) (Total 10 marks)
Limestone + clay = cement
Limestone + clay = cement + sand = mortar
Limestone + clay = cement + sand = mortar + aggregate = concrete
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ConsumeMoreChocolate?
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ConsumeMoreChocolate?
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ConsumeMoreChocolate?
+Clay+Sand+Aggregate
CementMortarConcrete
Other carbonates do the same
Thermal Decomposition
When Limestone is heated…
Why does the mass decrease?
