Question

In the DLVO theory of colloids, normal thermal motion may be sufficient to overcome the energy barrier that leads to irreversible particle aggregation. Which one of the following is the name of this energy barrier?

• A. Primary maximum
• B. Secondary maximum
• C. Primary minimum
• D. Secondary minimum

Answer 1

The Correct Option is A

Step 1: Understanding the DLVO theory. - The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory explains colloidal stability by considering the balance of van der Waals attraction and electrostatic repulsion. - Colloidal particles repel each other due to the electrical double layer, creating an energy barrier known as the Primary Maximum. 

Step 2: Explanation of energy barriers. - Primary maximum: The highest energy barrier that prevents particle aggregation. - Secondary maximum: A weaker repulsion that can lead to loose aggregation. - Primary minimum: The strong attraction region leading to irreversible coagulation. - Secondary minimum: A weak attractive force causing temporary aggregation. 

Step 3: Selecting the correct option. Since the primary maximum represents the energy barrier that prevents irreversible aggregation, the correct answer is (A) Primary maximum.