Gold number of a lyophic sol is such a property that

Options

A. The larger its value, the greater is the peptizing power.
B. The lower its value, the greater is the peptizing power.
C. The lower its value, the greater is the peptizing power.
D. The larger its value, the greater is the protecting power.

Explanation

To solve the question regarding the gold number of a lyophobic sol, we will follow these steps:

### Step-by-Step Solution:

1. **Define Gold Number**:
The gold number is defined as the minimum amount of a protective colloid (lyophilic sol) in milligrams that is required to prevent the coagulation of a specific volume (10 ml) of a gold sol when a certain amount (1 ml) of a 10% sodium chloride (NaCl) solution is added.

2. **Understanding Coagulation**:
Coagulation refers to the process where colloidal particles aggregate and settle out of the solution. The gold number indicates how effective a protective colloid is at preventing this process.

3. **Relationship Between Gold Number and Protecting Power**:
The gold number is inversely related to the protecting power of the colloid. This means:
- A **higher gold number** indicates that a larger amount of protective colloid is needed to prevent coagulation, which implies **less protecting power**.
- Conversely, a **lower gold number** means that only a small amount of protective colloid is needed, indicating **greater protecting power**.

4. **Conclusion**:
Based on the definition and the relationship established, we conclude that the correct statement regarding the gold number is: "Lower the value of gold number, greater is the protecting power."

### Final Answer:
The correct option is: **Lower the value, greater is the protecting power.**

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