Using Lime Flashcards
Explain what it does?
Limestone is often quarried out of the ground and is used to make blocks for building.
Limestone is calcium carbonate what is the symbol?
CaCO3
What’s made when it is thermally decomposed?
It makes calcium oxide and carbon dioxide.
What is limestone formed from?
Sea shells
Explain the thermal decomposition of calcium carbonate…
What is the symbol equation?
When calcium carbonate is heated it thermally decomposes to make calcium oxide and carbon dioxide.
CaCO3 + H2SO4 goes to CaSO4 + CO2 + H2O
Calcium carbonate + sulphuric acid goes to calcium sulphate + carbon dioxide + water
What is the definition of thermal decomposition?
Thermal decomposition is when one substance chemically changes into at least two new substances when it’s heated.
Explain thermal decomposition of magnesium, zinc and sodium carbonates…
When magnesium, copper, zinc and sodium carbonates are heated, they decompose in the same way. E.g. magnesium carbonate goes to magnesium oxide + carbon dioxide (MgCO3 goes to MgO + CO2).
Why can’t you do this experiment in class?
Because a Bunsen burner can’t reach a high enough temperature to thermally decompose some carbonates of Group 1 metals.
What do you get when you add water to calcium oxide?
You get calcium hydroxide
Explain the reaction of calcium oxide with water and of limewater…
Calcium hydroxide can also be used in a test for carbon dioxide. If you make a solution of calcium hydroxide in water (called limewater) and bubble gas through it, the solution will turn cloudy if there’s carbon dioxide in the gas. The cloudiness is caused by the formation of calcium carbonate.
What is the symbol equation?
Calcium hydroxide + carbon dioxide goes to calcium carbonate + water
Ca(OH)2 + CO2 goes to CaCO3 + H2O
