c1.2 limestone

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?

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

...........................................................................................................................

(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?