Extraction
Name the method used to extract limestone.
Quarrying
Give two uses of limestone.
Building material, making cement, extracting iron, making toothpaste, ground up as a source of calcium in bread etc.
What is the definition of thermal decomposition?
The breaking down of a compound using heat.
Describe the test (NOT the result) for carbon dioxide.
Bubble through limewater.
What is the POSITIVE RESULT when testing for carbon dioxide?
Limewater turns cloudy.
Give one advantage of extracting limestone.
Useful building material, provides jobs, money into local economy, better road systems, quarry converted into recreational facility after use etc.
Describe the expected observations when heating limestone.
Glowing (orange)
What are the products when a metal carbonate is thermally decomposed?
Metal carbonate and carbon dioxide.
What is the first stage in the limestone cycle?
Thermal decomposition of limestone (calcium carbonate).
What is the word equation for the thermal decomposition of copper carbonate?
Copper carbonate -> Copper oxide + Carbon dioxide
Give two disadvantages of extracting limestone.
Destruction of habitats, dust, noise, traffic etc.
What are the chemical name and formula of limestone?
Calcium carbonate, CaCO3
What is the relationship between reactivity of a metal and the stability of its carbonate?
As a metal's reactivity increases, the stability of its carbonate also increases.
What must be done to convert quicklime into slaked lime?
Add a few drops of water.
The conversion of quicklime to slaked lime is a very exothermic reaction. What does this mean?
Give your opinion on whether quarrying is a good or bad thing and provide THREE points to back up your answer.
Yes/No and three relevant supporting reasons from advantages/disadvantages.
What is the chemical name AND formula of quicklime?
Calcium oxide and CaO
Place the following metal carbonates in order of increasing thermal stability (from least to most stable).
Sodium carbonate, Calcium carbonate, Potassium carbonate, Copper carbonate
Copper carbonate (least stable)
Calcium carbonate
Sodium carbonate
Potassium carbonate (most stable)
In the reaction where quicklime is converted into slaked lime, what are the expected observations?
Hissing/steam produced/expanding/crumbling
Describe how to convert slaked lime into limewater.
Add excess water to product a solution of calcium carbonate.
Describe two measures that could be taken to reduce any negative impact a quarry might have.
Only 'blast' at certain times, limit the size of the quarry, remove endangered species to a safe site prior to using the quarry, convert to recreational facility after use, use trains instead of lorries, spray lorry wheels with water to reduce dust etc.
Calcium hydroxide comes in two forms. What are they?
Slaked lime (solid) and limewater (in solution).
Describe ONE experiment you could conduct to compare the thermal stability of two carbonates.
1. Heat separately and bubble the gas produced through limewater. The faster the limewater turns cloudy, the less stable the carbonate.
OR
2. Heat separately and allow the gas produced to escape. Measure the mass before and after heating. The more mass lost, the less stable the carbonate is.
Explain how limestone can be produced from limewater.
Bubble carbon dioxide through limewater until it becomes cloudy. The cloudiness is a white precipitate of calcium carbonate (limestone).
Give the symbol equation to show how quicklime is converted into slaked lime.
CaO(s) + H2O(l) -> Ca(OH)2(s)