Question

Discuss the significance of the gold number.

Answer 1

1. The gold number measures how effectively a lyophilic colloid (also known as a protective colloid) prevents the coagulation of a lyophobic gold sol when exposed to electrolytes.
2. It is defined as the minimum amount (mg) of protective colloid needed to prevent coagulation of 10 mL gold sol by 1 mL of 10% NaCl solution.
3. A smaller gold number indicates greater protective ability.
4. It helps compare the effectiveness of different protective colloids in stabilizing sols.