Chemistry Paper 1: C2
Materials
Earth structure
Salts
Fertalisers
Evidence needs to be repeatable and agreed for a theory to be accepted
Rock is recycled by geological process
Plate tectonic theory is now widely accepted
Scientists study volcanoes and earthquakes to try to predict future eruptions and seismic activity
Plate movements cause earthquakes and volcanoes
Metals are extracted from rocks
Alloys contain at least one metal but have different properties
Concrete is not very strong, but can be reinforced with steel
Copper is extracted by reduction and purified by electrolysis
Rocks are used as building material
Iron rusts in contact with oxygen and water and salt speeds up rusting
Aluminium is a metal with a low density, which does not corrode because it has a protective oxide layer
Fertilisers can cause eutrophication
Conditions for the Haber process can be adjusted to maximise yeild
Fertilisers can be made by a neutralisation reaction:
The Haber process is a reversible reaction that makes ammonia:
Ammonia is used to make nitrogen fertlisers
Sodium chloride is an important raw material which obtained by mining it from the ground or by solution mining
Electrolysis is used to split sodium chloride solution into hydrogen, Chlorine and sodium hydroxide
Acids react with metal oxides, hydroxides and carbonates to make salts
In electrolysis positive ions move to the cathode and negative ions move to the anode