Which of the following is/are negatively charged sol?

Options

A. Gold sol
B. Prussian blue dye
C. Haemolobin
D. Starch

Answer

To determine which of the given options are negatively charged sols, we can analyze each option based on their characteristics.

### Step-by-Step Solution:

1. **Understanding the Concept of Sols**:
- A sol is a colloidal solution where solid particles are dispersed in a liquid. The charge on these particles can be positive or negative, affecting their stability and interactions.

2. **Analyzing the Options**:
- **Option A: Gold Sol**:
- Gold sol (Au sol) is known to be negatively charged. This is due to the adsorption of negatively charged ions (AuO2-) on the surface of the gold particles, leading to a net negative charge.

- **Option B: Prussian Blue Dyes**:
- Prussian blue is a colloidal dye that is typically positively charged. Therefore, it does not qualify as a negatively charged sol.

- **Option C: Hemoglobin**:
- Hemoglobin is a protein that can also carry a positive charge in solution, making it a positively charged sol.

- **Option D: Starch Solution**:
- Starch can form a negatively charged sol due to the adsorption of negatively charged ions from the disperse phase, similar to gold sol.

3. **Conclusion**:
- Based on the analysis, the negatively charged sols from the given options are:
- **Gold Sol (Option A)**
- **Starch Solution (Option D)**

### Final Answer:
The negatively charged sols are **Gold Sol (A)** and **Starch Solution (D)**.

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