The Limestone Cycle

Question 1

How is cement made?

Answer 1

> limestone is crushed

> mixed with powdered clay

> and heated

Question 2

What are 2 uses of cement?

Answer 2

> mixed with sand and water to make mortar (what bricks are stuck together with)

> mixed with sand and aggregate to make concrete

Question 3

What are the disadvantages of limestone quarrying?

Answer 3

> noise pollution

> destroys landscape

> destroys habitats

> waste

> transportation causes pollution

> processing

• dust which can induce asthma
• fossil fuels create pollution

Question 4

What are the arguments for limestone quarrying?

Answer 4

> useful material for houses and roads
- chemicals in dyes paints and medicines can come from CaCO3

> used to neutralise acid lakes

> used in factories to neutralise SO2

> boosts local economy

> restoration of landscape is usually included in planning permission

Question 5

What are the advantages of concrete?

Answer 5

> can be built quickly and easily

> fire resistant

> non corroding

Question 6

What are the disadvantages of concrete?

Answer 6

> ugly

> low tensile strength

Question 7

Describe the limestone cycle.

Answer 7

> CaCO3 is thermally decomposed to form CaO and CO2

> water is added to form Ca(OH)2

> more water is added to form Ca(OH)2 (aq)

> CO2 is added to form CaCO3 once more, as a precipitate with water

Question 8

Why is limestone a good building material?

Answer 8

> strong

> durable

> can be easily cut

> attractive