limestone by abhishek jaguessar
TRANSCRIPT
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 1/15
LIMESTONEBY
ABHISHEKJAGUESSAR
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 2/15
What is limestone?
• It is a sedimentaryrock
• It was formed mainly
from sea shells• It is the compound
called calciumcarbonate
• It is a useful rawmaterial
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 3/15
What can limestone be used for?
• Building walls
• Building houses
• Limestone is alsoused to makecement and
concrete
• Neutralising excessacid in lakes or
soils
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 4/15
More about limestone
• Limestone is dug up out of the groundin quarries
• In Britain about 150 million tonnes of
limestone are quarried each year • Limestone is the compound calcium
carbonate
• It’s formula is CaCO3
• Limestone can be chemically changed
into other things
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 5/15
Heating limestone
• When limestone (calcium carbonate) isheated, it will break down (decompose)
• When something breaks down with heat
we call this reaction a ….
Thermal decomposition reaction• Calcium carbonate will have broken down
into calcium oxide and carbon dioxide• We call calcium oxide quicklime
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 6/15
A word equation for this reaction
Calcium heat calcium
carbon
Carbonate oxide
dioxide
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 7/15
Reacting quicklime with water
• Calcium oxide (quicklime) is a strong alkali
• It reacts with water to form calcium
hydroxide
• Calcium hydroxide is also known as
slaked lime
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 8/15
A word equation for this
reaction
calcium + water calcium
oxide hydroxide
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 9/15
Uses for slaked lime
• To neutralise acidic
soils, and to break up
the soil so that plants
can grow well
• To neutralise lakes
which have been
polluted by acid rain
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 10/15
Another use for calcium
hydroxide• Calcium hydroxide is also called limewater
• Limewater is used to test for the presenceof carbon dioxide gas
• We breathe out a lot of carbon dioxide
• If we blow through a straw into limewater itwill change from clear to milky-white
• The substance formed in this reaction isinsoluble calcium carbonate
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 11/15
A word equation for this
reaction
calcium + carbon calcium + water hydroxide dioxide carbonate
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 12/15
The Limestone Cycle
These reactions all make up the
limestone cycle.
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 13/15
limestone
Slaked lime
quicklimelimewater
heat
water more
water
carbondioxide
The limestone cycle
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 14/15
Tasks:
Use the worksheet called ‘The LimestoneCycle’ to fill in the gaps and complete the
equations for the reactions of limestone.
Copy out The Limestone Cycle.
Answer questions 1-5 on the nextworksheet
using the information given and your own
Knowledge. Afterwards copy out the
8/4/2019 Limestone by Abhishek Jaguessar
http://slidepdf.com/reader/full/limestone-by-abhishek-jaguessar 15/15
HOMEWORK
Complete the worksheet on
Questions on Limestone
for next lesson.