Geotechnical Engineering Questions and Answers – Clay Minerals

Geotechnical Engineering Objective Questions

This set of Geotechnical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Clay Minerals”.

1. There are __________ fundamental building blocks for the clay mineral structures.

A) 3
B) 5
C) 4
D) 2

Answer is D)
Explanation: Silica tetrahedral unit and octahedral unit are the 2 building blocks of clay mineral.

2. In silica tetrahedral unit, the silicon structure is enclosed by __________

A) Oxygen
B) Hydroxyls
C) Aluminum
D) None of the mentioned

Answer is A)
Explanation: In silica tetrahedral unit, four oxygen or hydroxyls have the configuration of tetra hadron.

3. Octahedral unit, consist atoms of __________ element.

A) Aluminum atom
B) Oxygen atom
C) Magnesium atom
D) All of the mentioned

Answer is D)
Explanation: In octahedral unit, aluminum, iron or magnesium atom are enclosed in six hydroxyls having the configuration of an octahedron.

4. The silicon sheet is represented by ___________ symbol.

A) trapezoidal
B) rectangle
C) triangle
D) none of the mentioned

Answer is A)
Explanation: The silicon sheet is represented by trapezoidal symbol, representing the oxygen basal layer and hydroxyl apex layer.

5. The 15 clay minerals are mainly divided in to ________ groups.

A) 3 groups
B) 2 groups
C) 9 groups
D) 4 groups

Answer is D)
Explanation: Clay minerals are classified into 3 groups of kaolin, montmorillonite, illite and palygorskite.

6. The kaolinite structural unit is made up of ____________ layer or sheet.

A) Gibbsite sheet
B) Silica sheet
C) Oxygen layer
D) Aluminum sheet

Answer is A)
Explanation: The kaolinite structural unit is made up of gibbsite sheet with aluminum atoms at their centers.

7. In kaolinite crystal, the layers are held by _________ bond.

A) Ionic bond
B) Cationic linkage
C) Hydrogen bond
D) Electro static bond

Answer is C)
Explanation: Since kaolinite is stable and water is unable to penetrate between the layers, they are held by a fairly strong bond of hydrogen.

8. Kaolinite exhibit the characteristic of ___________

A) Shrinkage limit
B) Plasticity
C) All of the mentioned
D) None of the mentioned

Answer is B)
Explanation: The platelets in kaolinite carry negative charges which attract thick layers of adsorbed water thereby producing plasticity.

9. An Example of kaolinite crystal or mineral is ___________

A) China clay
B) Crystal
C) Clay mineral
D) None of the mentioned

Answer is A)
Explanation: China clay show the property of plasticity, when mixed with water therefore it can be taken as an example for kaolinite crystal.

10. The illite crystal has a great tendency of _______________ properties.

A) Swelling
B) To split in to ultimate platelets
C) High shrinkage
D) None of the mentioned

... Answer is B)
Explanation: The cationic bond of illite is weaker than the hydrogen bond of kaolinite, but is stronger in water bond. Due to this, illite crystal has a great tendency to split in to ultimate platelets.