Haemoglobin and gold sol are examples of

Options

A. (A) positively and negatively charged sols, respectively
B. (B) negatively and positively charged sols, respectively
C. (C) positively charged sols
D. (D) negatively charged sols

Explanation

To solve the question regarding the nature of haemoglobin and gold sol, we need to classify these substances based on their charge as colloids.

### Step-by-Step Solution:

1. **Understanding Colloids**:
- Colloids are mixtures where one substance is dispersed evenly throughout another. They can be classified based on the charge of the dispersed particles.

2. **Identifying Haemoglobin**:
- Haemoglobin is a protein found in red blood cells that carries oxygen. It is known to have a positive charge in colloidal form due to its structure and the presence of amino acids that can donate protons.

3. **Identifying Gold Sol**:
- Gold sol is a colloidal suspension of gold particles. It is known that metal sols, including gold, typically carry a negative charge due to the nature of the metal particles and their interaction with the surrounding medium.

4. **Classifying the Charges**:
- Based on the above information, we can classify haemoglobin as a positively charged colloid and gold sol as a negatively charged colloid.

5. **Conclusion**:
- Therefore, haemoglobin and gold sol are examples of positively charged and negatively charged colloids, respectively.

### Final Answer:
Haemoglobin is a positively charged colloid, and gold sol is a negatively charged colloid.

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