C2.2 Limestone and Buildings

Question 1

How is limestone extracted?

Answer 1

It is quarried out of the ground

Question 2

What compound is limestone mainly composed of?

Answer 2

Calcium carbonate - CaCO3

Question 3

What products does the thermal decomposition of calcium carbonate (limestone) produce and what are their formulas?

Answer 3

Calcium oxide (CaO) Carbon dioxide (CO2)

Question 4

Why would be virtually impossible to thermally decompose group 1 metal carbonates in a school class?

Answer 4

A bunsen burner can’t reach a high enough temperature to decompose them

Question 5

Give four examples of carbonates that decompose in the same way as calcium carbonate.

Answer 5

• Sodium - Zinc - Copper - Magnesium

Question 6

What product does the reaction of calcium oxide with water produce and what is its formula?

Answer 6

Calcium hydroxide Ca(OH)2

Question 7

What is one use of calcium hydroxide and what is the property making this useful?

Answer 7

• It is used to neutralise acidic soil in fields as it is an alkali.

Question 8

Describe how calcium hydroxide is used as a test for carbon dioxide and give the resulting equation.

Answer 8

• If you make a solution of calcium hydroxide in water (limewater) and bubble gas through it, it will turn cloudy if it contains carbon dioxide, caused by the formation of calcium carbonate. calcium hydroxide + carbon dioxide ===> calcium carbonate

Question 9

Give the three equations of the limestone cycle.

Answer 9

calcium carbonate ===> calcium oxide + carbon dioxide calcium oxide + water ====> calcium hydroxide calcium hydroxide + carbon dioxide ===> calcium carbonate + water

Question 10

How is limestone used to make cement?

Answer 10

Powdered limestone and clay is heated in a hot kiln to make cement

Question 11

How is mortar made and what is it used for?

Answer 11

It is made by mixing cement with sand and water to stick bricks together with

Question 12

How is concrete made?

Answer 12

By mixing cement, sand and aggregate (water and gravel)

Question 13

What is glass a mixture of?

Answer 13

• Limestone - Sand - Soda

Question 14

How do carbonates react with acid?

Answer 14

To produce a salt, carbon dioxide and water i.e x carbonate + y acid ===> x y salt + carbon dioxide and water

Question 15

How does calcium carbonate react with sulfuric acid?

Answer 15

calcium carbonate + sulfuric acid ===> calcium sulfate + carbon dioxide + water

Question 16

What are the advantages of quarrying limestone?

Answer 16

• Limestone provides useful products - Limestone products are used to neutralise acidic soil and acidity in lakes and river caused by acid rain - Limestone can be used to neutralise sulfur dioxide in power station chimneys - It provides jobs for people and brings more money into the local economy leading to improvements in roads, health etc - Once it is complete, landscaping and restoration of the land is required

Question 17

What are useful products made from limestone (6)?

Answer 17

• Houses - Roads - Paints - Dyes - Paints - Machines

Question 18

What are the disadvantages of quarrying limestone? -

Answer 18

• Permanently damages the landscape - Creates noise - Creates dust which can cause breathing problems - Energy is needed for the process = more fossil fuels - Destroys animal habitats - Transportation causes more pollution - Waste materials cause tips

Question 19

What are the advantages of using limestone and its products?

Answer 19

• Widely available and cheaper than granite or marble - More hard wearing than marble - Concrete can be poured into moulds to make blocks - a quick and cheap way of constructing buildings - They don’t rot when wet - Fire-resistant - Concrete doesn’t corrode like metals

Question 20

What are the disadvantages of using limestone and its products?

Answer 20

• Concrete is unattractive - Concrete has a low tensile strength (cracks easily)

Question 21

What damages limestone?

Answer 21

Acid rain