2 Rocks And Building Materials Flashcards
What happens when we heat limestone?3
It breaks down to form
Calcium oxide + carbon dioxide
Thermal decomposition is what it’s called
What is limestone mainly made from?
Calcium carbonate
How is lots of calcium oxide made?2
In a furnace called a line kiln
How does a lime kiln work?4
- it is filled with crushed limestone
- heated strongly using a supply of hot air
- calcium oxide comes out of the bottom of the kiln
- waste gases, including the carbon dioxide made leave the kiln at the top
What is the chemical formula of calcium carbonate?
CaCO3
Other than building what can limestone be used to produce?2
Cement
Concrete
How can limestone be used to make cement?
it can be heated with powdered clay to make cement
What is calcium oxide useful for?
Building and farming industry
What happens when dilute acid is added to a carbonate?3
Carbonated react with dilute acid to form a salt, water and carbon dioxide
What is the test for carbon dioxide?2
- Limewater turns cloudy in the test for carbon dioxide gas
- a precipitate of insoluble calcium carbonate causes cloudiness
How can we make when calcium oxide reacts with water?
Calcium hydroxide
How can we make calcium hydroxide from calcium oxide?
When water is added to calcium oxide it produces calcium hydroxide
Why is calcium hydroxide a useful substance?
Calcium hydroxide is alkaline so it can be used to neutralise acids
How do we make concrete?4
- it is made by mixing crushed rocks or small stones called aggregate, cement and sand with water
How do we make cement?
It is made by heating limestone with clay in a kiln
What are the uses of limestone?
The building industry
What is a precipitate?
An insoluble solid formed by a reaction taking place in a solid
What does calcium oxide react with to produce calcium hydroxide?
Water
What does calcium hydroxide react with to produce calcium carbonate?
Carbon dioxide
Why are buildings made from limestone affected by the products from burning fossil fuels contains sulphur?
Sulphur burns to produce sulfur dioxide
That causes acid rain that erodes limestone
Why does nitrogen come out of a kiln?
Air does and 75-80% of air is nitrogen
Test for carbon dioxide in limewater?
Goes cloudy in limewater
Why does the production of low carbon steel use oxygen?
Oxygen is needed to react with carbon
Why does the production of titanium use argon?
Because it is very unreactive
Why is titanium more expensive than iron?
More stages in its manufacture
Larger amounts of energy needed
Argon is used