Question

Which of the following processes does not lead to coagulation?

• A. Heating of an egg in boiling water.
• B. Addition of an electrolyte to sol.
• C. Electrophoresis.
• D. Addition of water to gold sol.

Hint:

Coagulation typically requires actions that remove or neutralize charges on sol particles, such as heating, adding electrolytes, or using electrophoresis. Adding water, however, dilutes the sol and prevents coagulation.

Answer 1

The Correct Option is D

Step 1: Understanding coagulation.
Coagulation is the process of clumping together of particles in a sol, leading to the formation of a gel or precipitate. Certain actions like heating, addition of electrolytes, or electrophoresis can lead to coagulation. However, adding water to a sol often dilutes it, which does not promote coagulation.
Step 2: Analyzing the options.
(A) Heating of an egg in boiling water: Incorrect. Heating an egg leads to coagulation of proteins.
(B) Addition of an electrolyte to sol: Incorrect. Addition of electrolytes like NaCl to a sol can lead to coagulation by neutralizing the charges on sol particles.
(C) Electrophoresis: Incorrect. Electrophoresis causes particles to move toward electrodes, which may lead to coagulation.
(D) Addition of water to gold sol: Correct — Adding water dilutes the sol and prevents coagulation, making it the exception.
Step 3: Conclusion.
The correct answer is (D) Addition of water to gold sol, as it does not lead to coagulation.