Chemical weathering 3.2

Question 1

Chemical weathering

Answer 1

Involves decomposition of rocks, literally changing the minerals.

Question 2

Hydrolysis

Answer 2

Water reacts with the mineral in the rock, changing its chemical composition.
E.g Feldspar+water=clay

Question 3

Hydration

Answer 3

Minerals in rocks expand upon absorbing water and shrink upon drying, repeating the process eventually causes cracks and break down of the rock.

Question 4

Carbonation

Answer 4

Rocks such as limestone and chalk contain calcium carbonate CaCO3, Ca(HCO3)2 formed in contact with water, new material is soluble and is washed away.

Question 5

Oxidation

Answer 5

When water comes in contact with rocks containing Fe2+,mineral is oxidised and converted into Fe3+ causing a red coloration(rust) and the eventual crumbling of the rock.

Question 6

Acid Rain

Answer 6

Caused by greater concentration of CO2, Sulfur dioxide(SO2),nitrogen oxide(NO), mixing with water vapour and falling as acid rain, affecting limestone and chalk.