Limestone and building materials Flashcards
What can limestone be used for?
Building statues, cement, mortar and concrete
What are the negative impacts of quarrying limestone?
- noise, dust and other pollution
- spoil landscape
What are the positives of quarrying limestone?
- valuable material, positive economic impact
- employment
Describe the lime cycle
1) Calcium carbonate is heated to produce cacium oxide + carbon dioxide gas (thermal decomposition).
2) By adding water to calcium oxide we produce calcium hydroxide solid (alkali).
3) By adding more water calcium hydrxide solution (aq) is formed.
4) To turn this back to calcium carbonate you add carbon dioxide (by blowing) and the solid will start to form and turn the liquid cloudy. This can be used to test for carbon dioxide.
What are the features of calcium oxide?
-alkali that can be used to neutralise acidic soil and lakes
Why are some carbonates difficult to decompose?
carbonates at the top of group 1 in the periodic table are difficult to decompose therefore require more heat to allow thermal decomposition to take place.
What is the process of obtaining metals?
1) obtain a metal ore.
2) remove some impurities and concentrate the ore.
3) carry out a chemical reaction to remove the oxygen.
What is meant by an economically viable process?
Whereby removing a metal from it’s ore increases it’s value.
How can something become more economically viable?
If somebody finds a cheaper method or a method that extracts more metal.
What 5 metals are above carbon in the reactivity series?
Potassium, sodium, calcium, magnesium and aluminium.
What 7 metals are below carbon in the reactivity series?
Zinc, iron, tin, lead, copper, silver and gold.
How are metals extracted by reacting with a substance in the reactivity series?
If a substance is more reactive than a substance you want to extract then you can react them together (eg iron oxide and carbon) the non-metal (oxygen) is removed and reacted with the more reactive substance (carbon) which will make something like carbon dioxide and the pure metal that you wanted.
How is anything above carbon in th reactivity series extracted?
by being smelted in a furnace then having the impurities removed by electrolysis.
What is electrolysis?
the breaking down of a substance using electricity.
What is an electrolyte?
a liquid used to conduct electricity in electrolysis which are often metal salt solutions made from the ore (copper sulphate) or molten metal oxides.
