chemical weathering

Question 1

chelation

Answer 1

• weathering of rocks through the action of organic substances
• e.g. bacteria

Question 2

hydrolysis

Answer 2

• occurs on rocks with feldspar such as granite.
• feldspar reacts with acid water and forms kaolin
• acid and hydroxyl removed in solution

Question 3

carbonation

Answer 3

• dissolving of co2 in water
• produces carbonic acid
• reacts with calcium carbonate
• produces soluble calcium bicarbonate
• removed by percolating water

Question 4

hydration

Answer 4

• minerals change when they absorb water.
• results in expansion and contraction which leads to increased stress.
• some shales and mudstones can expand by 1600% when clay minerals absorb water
• makes more susceptible to other forms of weathering

Question 5

oxidation

Answer 5

• rust
• reaction between metal, oxygen and water
• forms brown outer layer, easily crumbles off