Question

Identify negatively charged sol from following.

• A. sol of clay
• B. $\text{Fe}_2\text{O}_3 \cdot x\text{H}_2\text{O}$
• C. $\text{TiO}_2$ sol
• D. Haemoglobin

Hint:

Most natural soil suspensions (clay, mud) and metallic sulfides are negatively charged, whereas basic dyes, blood, and metal oxides are positively charged.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
We need to identify the negatively charged colloidal sol among the given options.

Step 2: Detailed Explanation:
Colloidal sols are classified based on the nature of the electrical charge present on their dispersed particles.
Metallic oxides (like $\text{TiO}_2$ sol), hydrated metallic oxides (like $\text{Fe}_2\text{O}_3 \cdot x\text{H}_2\text{O}$), and biological fluids like haemoglobin (blood) are all classically categorized as positively charged sols.
On the other hand, naturally occurring sols of clay, charcoal, metallic sulfides (like $\text{As}_2\text{S}_3$), and metals (like copper or gold sols) are negatively charged.

Step 3: Final Answer:
The negatively charged sol is the sol of clay, which matches option (A).