The gold number of Gelatin Gum and Starch are 0.005 , 0.15 and 25 respectively . Which colloid has highest protection power ?

Options

A. Gelatin
B. Starch
C. Gum
D. All have equal protection power

Answer

To determine which colloid has the highest protective power based on their gold numbers, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Gold Number**:
The gold number is defined as the minimum mass of a colloid (in milligrams) required to prevent the coagulation of a gold sol when a specific amount of an electrolyte (like NaCl) is added. A lower gold number indicates a higher protective power.

2. **List the Gold Numbers**:
- Gelatin: 0.005
- Gum: 0.15
- Starch: 25

3. **Analyze the Gold Numbers**:
We need to compare the gold numbers of the three colloids. The smaller the gold number, the greater the protective power against coagulation.

4. **Identify the Lowest Gold Number**:
- Gelatin has a gold number of 0.005, which is the lowest among the three.
- Gum has a gold number of 0.15.
- Starch has a gold number of 25.

5. **Conclusion**:
Since gelatin has the lowest gold number (0.005), it has the highest protective power among the three colloids.

### Final Answer:
The colloid with the highest protective power is **Gelatin**.

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