Which of the silicate clays would likely have the highest level of potassium in the crystal ...

Which of the silicate clays would likely have the highest level of potassium in the crystal structure?
 
  A) fine-grained mica
  B) chlorite
  C) smectite
  D) vermiculite
  E) kaolinite

Question 2

Allophane differs from other silicate clays in all ways but one of the following:
 
  A) degree of crystallization of the particles
  B) the period of time it has been subject to weathering
  C) the presence of negative charges on the colloidal particles
  D) widespread occurrence around the world
  E) nature of parent materials from which it forms

Question 3

An alkaline soil contains 20 clay and 3 humus. If the pure clay has a CEC of 40 cmolc/kg and the humus 200 cmolc/kg, calculate the CEC/kg of the soil.
 
  A) 12 B) 16 C) 8 D) 30 E) 14

Question 4

A 1 kg soil sample has 2 cmolc of Al3+ on the exchange complex. Addition of which of the following would most effectively replace about half of this Al?
 
  A) 1 cmolc K+
  B) 10 cmolc OH-
  C) 4 cmolc Ca2+
  D) 2 cmolc Na+
  E) 4 cmolc Na+