Blood is a ………… charged sol.

Answer

**Step-by-Step Solution:**

1. **Understanding Colloids**: A colloid is a mixture where tiny particles are dispersed throughout another substance. Colloids can be charged, leading to two types: positively charged colloids and negatively charged colloids.

2. **Identifying Blood Components**: Blood contains various components, including cells and proteins. One significant protein in blood is hemoglobin, which is responsible for transporting oxygen.

3. **Charge of Hemoglobin**: Hemoglobin is known to carry a negative charge. This means that blood, as a whole, can be considered to have a positive charge because it contains other components that are positively charged.

4. **Coagulation and Flocculation**: Coagulation refers to the process where colloidal particles aggregate and form a precipitate when an electrolyte is added. This is important in understanding how blood behaves in the body.

5. **Role of Heparin**: In the human body, heparin acts as an anticoagulant, preventing the coagulation of blood. This ensures that blood remains fluid and does not clot unnecessarily.

6. **Conclusion**: Based on the presence of positively charged components in blood and the negatively charged hemoglobin, we conclude that blood is a positively charged sol.

**Final Answer**: Blood is a positively charged sol.

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