C1 2 Rocks and Building Materials Flashcards
What is limestone’s appearance like?
Pale yellow and grey rock
What is limestone mainly made up of?
Calcium carbonate
What is it made from?
Remains of tiny sea creatures
How do we gain limestone?
Through quarrying
What is limestone other than being a rock?
A building material.
What are the uses of limestone?
Glass, cement, concrete, mortar, used in the extraction of iron
What process is used to heat limestone?
Thermal decomposition
What is thermal decomposition?
Breaking down a chemical through heating
What is limestone broken down into in thermal decomposition?
CaCO3 —-> CaO + CO2
Where does the thermal decomposition take place?
In a rotary kiln
What comes in and comes out of a rotary kiln?
Limestone and clay is put in and so is methane and air (from the surroundings), nitrogen, argon and carbon dioxide come out from burning methane and the decomposition of limestone. Nitrogen and argon are also unreactive. Calcium oxide also comes out.
How do you test for carbon dioxide?
Limewater is used (calcium hydroxide solution - alkaline) and the weakly acidic CO2 from our exhaling (blowing) reacts. A precipitate is formed (calcium carbonate) which makes the substance cloudy - no light is able to pass through solid.
What are the products when a carbonate react with an acid?
A salt, water and CO2
What does decomposing carbonates produce?
The metal oxide and CO2
How does an alkali neutralise an acid by reacting with it?
It produces a metal and water.