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
Explain how products from burning coal have an impact on the environment?
Carbon dioxide causes global warming
Carbon particles cause global dimming
Carbon monoxide is toxic
Sulfur dioxide causes acid rain
What does burning methane produced?
Carbon dioxide
Water
How much nitrogen is in the air?
78%
Why can metals be bent and hammered into different shapes?
Layers of atoms that can slide over eachother
How does limestone release carbon dioxide?
Thermal decomposition
How does limestone remove sulphur dioxide?
Reacts with sulphur dioxide to form calcium sulfate
Neutralised
Explain how carbon monoxide is formed?
Incomplete combustion due to lack of oxygen
Explain the meaning of locked up carbon dioxide?
Carbon dioxide from the atmosphere
Taken in millions of years ago
Used to form shells or skeletons
of marine organisms
What does calcium carbonate decompose to be?
Calcium oxide and carbon dioxide
What decomposes in a similar way to calcium carbonate?
Magnesium
Copper
Zinc
Sodium
What do metal carbonates decompose (on heating) to produce?
Carbon dioxide and metal oxide
What is the test for carbon dioxide?
Carbon dioxide turns limewater cloudy
What do carbonates react with acids to produced
Carbon dioxide
A salt
Water
What happens when limestone is heated with clay?
Makes cement
How is cement used to make mortar?
It’s mixed with sand
How do you make concrete from cement?
Mix cement with sand and aggregate
What does a solution of calcium hydroxide in water react with carbon dioxide to produce?
Calcium carbonate
What is limewater?
Calcium hydroxide in water
What does limestone thermally decompose to produce?
Calcium oxide
And carbon dioxide
How do you make calcium hydroxide solution from calcium hydroxide?
Add more water and filter
Why use a limestone kiln?
You can make lots of calcium oxide
Why rotate a kiln?
So there is a proper supply of air
So the calcium carbonate decomposed completely
What is the test for carbon dioxide?
Turns limewater solution cloudy
Describe how the limewater test works?
Limewater is alkaline calcium hydroxide
Carbon dioxide is weakly acidic
They react to form precipitate of calcium carbonate
Which turns the limewater cloudy
As light can’t pass through solution with solid in it
How is calcium hydroxide used?
To improve soul is acidic because it is an alkali
It will raise the ph of an acidic soil
Neutralise acidic waste gases before releasing gases in the air
How is concrete used?
Glass fibres
Carbon fibres
Steel rods
Poly propene nylon
What are metals always?
Positive
What are non metals always?
Negative
Why don’t we react carbon with titanium?
It is made brittle
What are the simplest steels?
Carbon steels
Why is concrete stronger than mortar
Contains more aggregate
Why is scrap iron used to get copper?
It is cheap
Advantages of phytomining?
Carbon neutral
Less expensive for small amounts
Disadvantage of phytomining?
Not continuous as it takes too long for plants to grow
Why is iron straight from a blast furnace not useful?
It’s very brittle
Very hard
Can’t be compressed easily
How do you treat iron in a blast furnace?
To remove some of the carbon to give us pure iron
How do you make carbon steels?
By removing most of the carbon from cast iron
What does distillation do?
Separated liquids with different boiling points
