Unit 1 - Chapter 2

Limestone & its Uses
1. Its Uses
  1. Neutralising
  2. Buildings
  3. Toothpaste
  4. Concrete
  5. Glass
2. Calcium Carbonate: CaCO3
3. Found in the ground
4. A pale white-ish rock
5. Thermal Decomposition: When a substance is heated it will break down into simpler substances
  1. Metal Carbonate --> Metal Oxide + Carbon dioxide
    1. This happens with similar effects with all metals in group 2 e.g Magnesium Carbonate --> Magnesium Oxide + Carbon dioxide
  2. CaCO3 --> CaO + CO2
Reactions of Carbonates
1. Limestone Statues are affected by acid rain
2. Testing for Carbon Dioxide
  1. Limewater is a solution of Calcium Hydroxide. It is alkaline!
  2. Carbon Dioxide is a weak acidic gas so it reacts with the Limewater.
  3. Tiny particles of insoluble Calcium Carbonate are formed. This makes it look cloudy.
  4. Limewater + Carbon Dioxide = Calcium Carbonate + Water
  5. Ca(OH)2 + CO2 = CaCO3 + H2O
3. Carbonate + Acid = Salt + Water + Carbon Dioxide
4. Calcium Carbonate + Hydrochloric Acid = Calcium Chloride + Water + Carbon Dioxide
  1. CaCO3 + 2HCl = CaCl2 + H2O + CO2
The Limestone Cycle
2. Step 2 is important - If we add water to Calcium Oxide we get limewater!
3. Nuetralizing Acids
  1. Calcium Hydroxide is an alkali. It can neutralise acids to create calcium salt and water.
  2. is used to neutralise soil and harmful acidic gases given of by factories.

Resource summary

	Created by brandon.fletcher about 10 years ago