Question

K fixing power of clay minerals follows the order:
(A) Illite
(B) Montmorillonite
(C) Kaolinite
(D) Vermiculite

• A. (A), (B), (C), (D)
• B. (D), (A), (B), (C)
• C. (B), (A), (D), (C)
• D. (C), (B), (D), (A)

Hint:

K fixation depends on the layer charge and interlayer spaces in clay minerals.

Answer 1

The Correct Option is B

Step 1: K-fixation depends on interlayer charge and spacing of the clay mineral.
Step 2: Vermiculite fixes K most strongly, followed by illite, then montmorillonite.
Step 3: Kaolinite, a non-expanding 1:1 mineral, fixes almost no K.
Step 4: Correct order, (D), (A), (B), (C).