C1.2 Limestone and building materials

Question 1

What is limestone mainly made of?

Answer 1

Calcium Carbonate - CaCO3*

Question 2

What is thermal decomposition?

Answer 2

When one substance chemically changes into at least two new substances when it is heated

Question 3

What is the word equation of the thermal decomposition of calcium carbonate?

Answer 3

Calcium Carbonate ==> Calcium Oxide + Carbon Dioxide

Question 4

What is produced when a metal carbonate reacts with an acid?

Answer 4

A salt, carbon dioxide and water is produced

Question 5

What is the word equation of Calcium Carbonate with an acid?

Answer 5

Calcium Carbonate + acid ==> Calcium Salt + Carbon Dioxide + water

Question 6

If CaCO3* reacted with sulphuric acid what salt would be produced?

Answer 6

Calcium Sulfate

Question 7

Besides Calcium, what other metal carbonates react with acid to make a salt, carbon dioxide and water? (4)

Answer 7

Magnesium, copper, zinc and sodium

Question 8

What is produced when water is added to calcium oxide?

Answer 8

Calcium Hydroxide

Question 9

What is the word equation for calcium oxide and water?

Answer 9

Calcium Oxide + water ==> Calcium Hydroxide

Question 10

What can Calcium Hydroxide be used for?

Answer 10

It’s alkali, so it is used to neutralise acidic - limestone powder also does this but calcium hydroxide acts much faster

Question 11

What is the test for Carbon Dioxide?

Answer 11

Limewater, which is calcium hydroxide in water, turns cloudy from clear when CO2* is present, this is because calcium carbonate is produced which is insoluble

Question 12

What is the word equation for the carbon dioxide test?

Answer 12

Calcium Hydroxide + Carbon Dioxide ==> Calcium Carbonate + water

Question 13

Why is limestone used as a building material?

Answer 13

Because it is widely available and is cheap. It is also easy to cut in to shapes and is hard wearing

Question 14

How is cement made?

Answer 14

Powdered limestone is heated in a kiln with powdered clay to make cement

Question 15

How is mortar made? What is it used for?

Answer 15

Cement is mixed with sand and water to make mortar - which is used to stick bricks together

Question 16

How is concrete made?

Answer 16

Cement is mixed with sand and aggregate (water and gravel)

Question 17

What qualities makes limestone, cement and concrete good building materials?

Answer 17

They don’t rot when they get wet like wood, they can’t get gnawed by insects/rodents and they’re fire resistant

Question 18

What makes concrete a good building material?

Answer 18

It can be poured into moulds to make blocks/panels that can be joined together, it’s a quick, cheap way of constructing buildings and it doesn’t corrode like most metals

Question 19

Besides as a building material, what other uses are there of limestone?

Answer 19

Used in dyes, paints and medicine, limestone products are to neutralise acidic soil, used in power station chimneys to neutralise sulfur dioxide (which is a cause of acid rain) and limestone quarries provide local jobs and bring money into the local economy

Question 20

What problems at there with quarrying limestone?

Answer 20

It involves making huge holes which ruins the landscape, explosives used to quarry limestone creates noise pollution and creates dust, it destroys habitats and the limestone is transported away in lorries which produce noise, traffic and pollution

Question 21

What drawbacks are there to limestone products?

Answer 21

Cement factories make lots of dust which can cause breathing problems, energy from fossil fuels is used to make cement which causes pollution and concrete is very unattractive and can crack

Question 22

How can you stop concrete from cracking?

Answer 22

You could reinforce it with steel bars