Question

Which mineral clay is known for its high cation exchange capacity?

• A. Kaolinite
• B. Vermiculite
• C. Montmorillonite
• D. Illite

Hint:

Cation Exchange Capacity (CEC):
- Montmorillonite: 80-150 cmol/kg (high).
- Vermiculite: 100-200 cmol/kg (very high).
- Illite: 20-40 cmol/kg (medium).
- Kaolinite: 3-15 cmol/kg (low).

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
This question tests knowledge of clay minerals and their cation exchange capacity (CEC).

Step 2: Detailed Explanation:
Montmorillonite (C) is known for its high cation exchange capacity (CEC).
It has a CEC of 80-150 cmol/kg.
It is a 2:1 clay mineral with high specific surface area.
Other clay minerals:
- Kaolinite (A): Low CEC (3-15 cmol/kg).
- Vermiculite (B): High CEC (100-200 cmol/kg) but not as common as montmorillonite.
- Illite (D): Medium CEC (20-40 cmol/kg).
Thus, montmorillonite has high CEC.

Step 3: Final Answer:
Thus, montmorillonite is known for its high cation exchange capacity, which corresponds to option (C).
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