Please Answer:

CALCULATION QUESTION 1

(A) Calculate the number of cmol of Al3+ cations needed to replace 10 cmolc of Ca2+ by cation exchange in a soil.

(B) How many grams of Al3+ does this correspond to? (you’ll need the atomic weight of Al, which is 27 g/mol, to calculate this)

CALCULATION QUESTION 2

A soil sample (500 g) contains the following amounts of exchangeable cations: Ca2+= 9 cmolc , Mg2+= 3 cmolc , K+= 1 cmolc , Al3+= 3 cmolc .

(A) What is the CEC of this soil (in cmolc/kg)?

(B) What is the aluminum saturation of this soil?

(C) What is the amount (in cmol) of exchangeable Ca2+ present in 1 kg of this soil?

CALCULATION QUESTION 3

A 100 gram sample of a soil has been determined to contain exchangeable cations in the following amounts: Ca2+= 90 mg; Mg2+= 35 mg; K+= 28 mg; Al3+= 60 mg.

(A) What is the CEC of this soil (in cmolc/kg)?

(B) What is the aluminum saturation of this soil?

(Note that 1 mg=1 milligram = 1/1000 g = 0.001 g) (You will need the atomic weights of the cations, which are as follows: Ca = 40.1; Mg = 24.3; K = 39.1; Al = 27.0)