The gold number range of some of the lyophilic colloids is given below:

A: 0.005 - 0.01

B. 0.15 - 0.25

C. 0.04 - 1.0

D. 15 - 25

Which among these can be used as a better protective colloid?

A

The correct answer is option 1. A.

The Gold number is a measure of the protective power of a lyophilic colloid, particularly in preventing the coagulation or precipitation of a lyophobic sol (a colloidal solution where the dispersed phase and dispersion medium are immiscible or insoluble in each other).

A lower Gold number indicates better protective colloidal behavior because it means that smaller amounts of the lyophilic colloid are needed to prevent coagulation. This is because the protective colloid forms a stable layer around the dispersed particles, preventing them from coming together and precipitating out of the solution.

Given the ranges provided:

A: 0.005 - 0.01

B: 0.15 - 0.25

C: 0.04 - 1.0

D: 15 - 25

Range A has the lowest values, indicating that a smaller amount of the colloid is needed for effective protection against coagulation. In contrast, range D has the highest values, suggesting that a larger amount of the colloid is required for effective protection.

Therefore, range A (0.005 - 0.01) can be considered as a better protective colloid compared to the other options because it requires the least amount of colloid to achieve stable colloidal behavior.