5.1 How and why do rocks disintegrate to form sediment?
potassium feldspar water
2 KAlSi3O8(s) + 11 H2O
2 K+(aq) + 2 OH-(aq) + 4 H4SiO4(aq) + Al2Si2O5(OH)4(s)
potassium and hydroxyl ions silicic acid kaolinite
Fig 5.4c