1. L.O: To know what limestone is and how it can be decomposed using heat

2. Limestone Marble Calcium carbonate Chalk Calcite Travertine Tufa Limeshell Coral Marl

3. Limestone is a sedimentary rock. It comes from the shells of sea creatures or from solids formed in the oceans long ago. It is mostly made of calcium carbonate - CaCO 3. It is an important raw material for both the chemical and the construction industries.

5. What do you predict? Look at the available equipment for a hint! What do you think the word equation is?

6. 1. Making quicklime from limestone Heat a spatula of calcium carbonate in a test tube. Clamp the test tube above the bunsen and use a delivery tube connected to limewater to see if carbon dioxide is given off. 11/10/2015

7. Quicklime - the lime kiln Limestone is heated in huge ovens known as lime kilns. The calcium carbonate decomposes into calcium oxide (quicklime) and carbon dioxide. Quicklime is a vital ingredient of cement, concrete and of most types of glass. CaCO 3 CaO + CO 2

8. Water can now be added. What would the word equation be now? 11/10/2015

9. Slaked lime If water is added to quicklime the calcium oxide changes into calcium hydroxide (slaked lime). Slaked lime is a vital ingredient of various building materials. CaO + H 2 O  Ca(OH) 2 A solution of calcium hydroxide (limewater) is also used to test for carbon dioxide gas (it goes cloudy).

10. Limestone Cycle experiment 2.Turning quicklime into slaked lime Tip the quicklime into a watch glass and add a few drops of water. Test this substance with UI. If calcium hydroxide has been made (an alkali) the UI will go purple. 11/10/2015

11. The “Limestone Cycle” Calcium Carbonate (limestone) Calcium Oxide (lime or quicklime) Calcium Hydroxide (slaked lime) Calcium Hydroxide solution (limewater) Step 1: heat Step 2: add a little water Step 3: add more water and filter Step 4: add CO 2 CO 2 H2OH2OH2OH2OH2OH2OH2OH2O

12. 11/10/2015Limestone If soil is too _____ crops will fail. Limestone can also be used as a neutralising agent. There are two reactions to know: 1) Firstly, a THERMAL _________________ reaction is used to break the calcium carbonate down into calcium oxide (quicklime) and _______ __________: 2) This is then “slaked” with water to produce calcium hydroxide (“_________ lime”): Calcium hydroxide is alkaline and is used to ______ acidic soil. Calcium carbonate calcium oxide + carbon dioxide HEAT Calcium oxide + water calcium hydroxide Words – slaked, acidic, neutralise, decomposition, carbon dioxide