Dayanaprya

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Dayanaprya

  1. 1. and its uses
  2. 2. LIME STONE BY S.DAYANA PRIYA
  3. 3. What is limestone? • It is a sedimentary rock • It was formed mainly from sea shells • It is the compound called calcium carbonate • It is a useful raw material
  4. 4. What can limestone be used for? • Building walls • Building houses • Limestone is also used to make cement and concrete • Neutralising excess acid in lakes or soils
  5. 5. More about limestone • Limestone is dug up out of the ground in 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
  6. 6. Heating limestone • When limestone (calcium carbonate) is heated, 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
  7. 7. A word equation for this reaction Calcium heat calcium carbon Carbonate oxide dioxide
  8. 8. 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
  9. 9. A word equation for this reaction calcium + water calcium oxide hydroxide
  10. 10. 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
  11. 11. Another use for calcium hydroxide • Calcium hydroxide is also called limewater • Limewater is used to test for the presence of carbon dioxide gas • We breathe out a lot of carbon dioxide • If we blow through a straw into limewater it will change from clear to milky-white • The substance formed in this reaction is insoluble calcium carbonate
  12. 12. A word equation for this reaction calcium + carbon calcium + water hydroxide dioxide carbonate
  13. 13. The Limestone Cycle These reactions all make up the limestone cycle.
  14. 14. limestone Slaked lime quicklimelimewater heat watermore water carbon dioxide The limestone cycle
  15. 15. I WANT TO THANK VIJAYAM INSTITUTION&CORRESPON DENT SIR FOR GIVING ME THIS OPPURTUNITY AND THEN I WANT TO THANK PRASAD SIR AND NALINI MADAM.
  16. 16. THANK YOU
  17. 17. This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.

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