Which of the following has minimum protecting power ?

Options

A. Gelatin (Gold no . = 0.01 )
B. Dextrin ( Gold no = 15)
C. Potato starch ( Gold no . = 25)
D. Albumin ( Gold no . = 0.25)

Answer

To determine which of the given options has the minimum protecting power, we need to analyze the gold numbers of the substances provided. The gold number is a measure of the protective power of a colloid; a higher gold number indicates a lower protective power.

### Step-by-Step Solution:

1. **Understand the Gold Number**:
- The gold number is defined as the minimum amount of protective colloid (in milligrams) required to prevent the flocculation of 10 ml of a gold sol when 1 ml of a 10% NaCl solution is added.

2. **Identify the Relation**:
- The gold number has an inverse relationship with the protective power of the colloid. This means that a higher gold number indicates a lower protective power, and vice versa.

3. **List the Gold Numbers**:
- We need to know the gold numbers for the options given:
- Gelatin: Gold number (lower value indicates higher protective power)
- Dextrin: Gold number
- Potato Starch: Gold number
- Albumin: Gold number

4. **Compare the Gold Numbers**:
- Without specific values provided in the question, we typically know from literature that:
- Gelatin has a low gold number (high protective power).
- Albumin has a moderate gold number.
- Dextrin has a higher gold number than gelatin but lower than potato starch.
- Potato starch has the highest gold number (indicating the lowest protective power).

5. **Conclusion**:
- Since potato starch has the highest gold number, it has the minimum protecting power among the options given.

### Final Answer:
**Potato Starch has the minimum protecting power.**

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