POLLUTION

Question 1

Acidification of freshwaters

Answer 1

natural pH of rainfall is 5.6 due to reaction of carbon dioxide and rainfall =
CO2+H20=H2CO3 (carbonic acid) = non anthroprogenic acidification

anthrophegenic = caused by burning of fossil fuels, vechiles and power plants etc and deposition of acids on earth into lakes and streams, trees and call this acid rain, pH less than natural 5.6

acid rain = when sulfuric dioxide and nitrogen oxides released into atmosphere from fossil fuels, react with water vapour and oxygen to form sulfuric acid and nitric acid to mix with precipitation and fall to ground as acid rain
wet deposition = occurs when acidic compunds dissolve in water and fall as rain, US has rain with pH of 4-5
dry = acidic gases settling on surfaces without precipitation

Question 2

causes of acidification

Answer 2

1) Industrial atmospheric pollution from oil and coal burning power stations and industrial plants forms sulphuric acid
2) NOx from car exhausts power stations and combustions forms nitric acid
3) land use change such as afforestation - carbon sequestrian issues because trees act as carbon sink, if replace grasslnad with trees it may dirupt carbon cycles

Question 3

wet deposition

Answer 3

1) nothing/granite if little buffering capacity, no ability to sbsorb, lakes remians acid, acidification of surfce water and can kill plants
2) limestone, rich in calcium carbonate and can- Calcium bicarbonate (Ca(HCO₃)₂) reacts with H⁺ and SO₄²⁻, forming calcium sulfate (CaSO₄), carbon dioxide (CO₂), and water (H₂O).
- Ca²⁺ ions in limestone-rich soils help buffer acidity, preventing excessive pH drops.

Question 4

dry deposition