AQA GCSE science on pages 100 & 101
Limestone
In the city of Bath in south west England the houses and shops of the city are made from Bath stone. Bath stone is a type of limestone. Limestone was formed from the shells of creatures that lived in shallow seas between 440 and 70 million years ago. Limestone is an important building material because it is attractive, strong and durable. Some limestone is crushed into small lumps to make aggregate. Aggregate is used as a firm base underneath railway lines and roads. Limestone is also a raw material for the production of other useful building materials, including cement, mortar and glass.
Acid Attack
The surface of limestone can be damaged by chemical reactions with acid rain. This may make gaps between blocks in buildings. The damage happens because limestone consists mainly of calcium carbonate, CaCO3.
Calcium carbonate reacts with acids to make a salt, water and carbon dioxide. For example with sulfuric acid, an acid rain acid, the equation is:
Calcium carbonate + Sulfuric acid -----> Calcium sulfate + Carbon dioxide + Water
CaCO3 + H2SO4 -----> CaSO4 + CO2 + H2O
Other carbonates react in similar ways with acid. For example:
Magnesium carbonate + Hydrochloric acid ----> Magnesium chloride + Carbon dioxide + Water
Calcium carbonate reacts with acids to make a salt, water and carbon dioxide. For example with sulfuric acid, an acid rain acid, the equation is:
Calcium carbonate + Sulfuric acid -----> Calcium sulfate + Carbon dioxide + Water
CaCO3 + H2SO4 -----> CaSO4 + CO2 + H2O
Other carbonates react in similar ways with acid. For example:
Magnesium carbonate + Hydrochloric acid ----> Magnesium chloride + Carbon dioxide + Water
Quarry queries
Companies get limestone from quarries which are large holes in the ground. They use explosives to break up the rock before digging it out. Quarries bring benefits and problems.
Benefits
Many quarries are in the countryside. Here, they provide jobs in places where work may be scarce. This helps local families and facilities such as shops and schools. These are the social impacts of quarrying.
Products from quarries are valuable. Each year, British quarries produce materials worth several billion pounds. Although, the UK imports some limestone, it exports even more. This contributes to the nations economy. These are economic impacts of digging rocks from the ground.
Products from quarries are valuable. Each year, British quarries produce materials worth several billion pounds. Although, the UK imports some limestone, it exports even more. This contributes to the nations economy. These are economic impacts of digging rocks from the ground.
Problems
Some quarries are in attractive areas of the countryside, where they may damage tourist industry. Transporting rocks from quarries to customer creates extra traffic, which may pass through small towns or villages.
Quarries also have environmental impacts. For example they take up land space, making the land unavailable for other uses such as farming and recreation.
Quarries also have environmental impacts. For example they take up land space, making the land unavailable for other uses such as farming and recreation.
Learning Objectives
Limestone, Aggregate, Social impact, Economic impact, Environmental impact. |
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