Question

1:1 type of layer silicate clay is

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

Hint:

1:1 Clay = Kaolinite.
2:1 Expanding = Montmorillonite, Vermiculite.
2:1 Non-expanding = Illite.
2:1:1 = Chlorite.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Layer phyllosilicates are classified based on the ratio of silicon-oxygen tetrahedral sheets to aluminum/magnesium octahedral sheets in their basic crystal unit.
Key Formula or Approach:
\[ \text{1:1 Layer Silicate} = 1\text{ Silica Tetrahedral Sheet} + 1\text{ Alumina Octahedral Sheet} \]

Step 2: Detailed Explanation:
Classification of silicate clay minerals:
1. 1:1 Type: Kaolinite, Halloysite, Dickite. Each crystal layer consists of one silicon tetrahedral sheet and one aluminum octahedral sheet held rigidly by hydrogen bonds.
2. 2:1 Expanding Type: Montmorillonite, Smectite, Vermiculite.
3. 2:1 Non-Expanding Type: Illite (fine-grained mica).
4. 2:1:1 (or 2:2) Type: Chlorite.

Step 3: Final Answer:
Hence, the 1:1 type layer silicate clay is Kaolinite, matching option (B).