Which of the following has minimum protecting power ?

Options

A. Gelatin (Gold no . = 0 . 0 1)
B. Dextrin (Gold no = 15)
C. Potato starch (Gold no . = 25)
D. Albumin (Gold no . = 0 . 25)

Answer

To determine which of the given substances has the minimum protecting power, we need to analyze the gold numbers associated with each substance. The substances provided are gelatin, dextrin, potash starch, and albumin, with their respective gold numbers as follows:

- Gelatin: 0.01
- Dextrin: 15
- Potash starch: 25
- Albumin: 25

**Step 1: Understand the concept of Gold Number**
The gold number is defined as the minimum amount of a lyophilic colloid (protective colloid) required to prevent the coagulation of a lyophobic colloid when an electrolyte is added. A lower gold number indicates a higher protecting power, as less of the protective colloid is needed to prevent coagulation.

**Step 2: Compare the Gold Numbers**
Now, we compare the gold numbers of the substances:
- Gelatin: 0.01 (highest protecting power)
- Dextrin: 15
- Potash starch: 25 (lowest protecting power)
- Albumin: 25 (lowest protecting power)

**Step 3: Identify the substance with the highest Gold Number**
The substance with the highest gold number will have the minimum protecting power. In this case, both potash starch and albumin have the highest gold number of 25.

**Conclusion:**
Since potash starch and albumin both have the same highest gold number, they both exhibit minimum protecting power. However, since the question asks for which has minimum protecting power, we can choose either of them. For the sake of this solution, we will select potash starch.

**Final Answer: Potash starch has minimum protecting power.**

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