Question

Which of the following protective colloids has a high gold number?

• A. Acacia
• B. Tragacanth
• C. Albumin
• D. Gelatin

Hint:

- The gold number measures the protective power of a colloid, with higher values indicating better stability of colloidal dispersions. 
- Tragacanth has the highest gold number among common protective colloids, making it highly effective in stabilizing colloidal solutions.

Answer 1

The Correct Option is B

The gold number is a measure of the protective power of a colloid, defined as the minimum amount (in mg) of colloid required to prevent the precipitation of 10 mL of gold sol when added to the sol. A higher gold number indicates a greater protective power, meaning the colloid is better at stabilizing the sol. Among the options: 
- Tragacanth has the highest gold number, indicating it has the greatest ability to protect a colloidal gold sol from precipitation. It is widely used in various pharmaceutical formulations for this reason. 
- Acacia, Albumin, and Gelatin are also used as protective colloids, but their gold numbers are generally lower compared to Tragacanth. Thus, the correct answer is Tragacanth, which has a high gold number. 

Why Other Options Are Incorrect: 
- (A) Acacia: While Acacia is commonly used as a protective colloid, its gold number is not as high as Tragacanth. 
- (C) Albumin: Albumin is a protein with protective colloidal properties, but it has a lower gold number compared to Tragacanth. 
- (D) Gelatin: Gelatin has protective colloidal properties but does not have as high a gold number as Tragacanth.