Which of the following statement is true?

Options

A. Lower the gold number, more will be protective power
B. Higher the gold number more will be the protective power
C. Higher the coagulation value, more will be coagulation power
D. none of these

Explanation

To determine which of the statements provided is true, we will analyze each statement in detail.

### Step-by-Step Solution:

1. **Understanding Gold Number:**
- The gold number is defined as the minimum amount of protective colloid (in milligrams) that must be added to 10 ml of a standard gold salt solution to prevent its coagulation when 1 ml of a 10% NaCl solution is added.
- This means that a lower gold number indicates a higher protective power of the colloid because less protective colloid is needed to prevent coagulation.

**Hint:** Remember that a lower gold number means more effective protection against coagulation.

2. **Analyzing Statement A:**
- Statement A claims that "lower the gold number, more will be the protective power of the colloid."
- Since we established that a lower gold number indicates a higher protective power, this statement is **true**.

**Hint:** Compare the definitions of gold number and protective power to validate this statement.

3. **Analyzing Statement B:**
- Statement B is not provided in detail, but we can assume it is false based on the context of the discussion.
- Without specific content, we cannot analyze it further.

**Hint:** Look for contradictions in the definitions or relationships discussed to identify false statements.

4. **Understanding Coagulation Value:**
- The coagulation value is defined as the minimum concentration of an electrolyte (in millimoles per liter) required to cause coagulation.
- A higher coagulation value means that a larger concentration of electrolyte is needed to cause coagulation, which implies a lower coagulation power.

**Hint:** Remember that coagulation value and coagulation power are inversely related.

5. **Analyzing Statement C:**
- Statement C claims that "higher the coagulation value, more will be the coagulation power."
- This statement is incorrect because a higher coagulation value indicates that more electrolyte is needed, which means the coagulation power is actually lower.

**Hint:** Use the relationship between coagulation value and coagulation power to assess the truth of this statement.

### Conclusion:
- After analyzing all statements, we conclude that **Statement A is true**.

### Final Answer:
The correct answer is **Statement A**: "Lower the gold number, more will be the protective power of the colloid."