The maximum fixation of K occurs

A. In 1 : 1 type clay minerals

B. In 1 : 2 type clay minerals

C. In 2 : 2 type clay minerals

D. In 2 : 1 type clay minerals

Answer: Option D

Solution(By Examveda Team)

The maximum fixation of K occurs in 2 : 1 type clay minerals.
The major minerals responsible for K fixation are illite, vermiculite and smectite. It has been demonstrated that vermiculite and smectite minerals have more ability to fix K compared to other 2 : 1 minerals due to the higher specific surface area and negative layered charge.