Bredig's arc method is used for the preparation of colloidal solution of :

Options

A. All lyophobic sol
B. Lyophilic sol
C. Associated sol
D. Lyophobic metal sols

Answer

**Step-by-Step Solution:**

1. **Understanding Bredig's Arc Method**: Bredig's arc method is a technique used to prepare colloidal solutions. It involves creating an electric arc between two electrodes made of a metal.

2. **Setting Up the Experiment**: The electrodes are immersed in a dispersion medium (usually water or another liquid). This setup is crucial for the preparation of colloidal solutions.

3. **Creating the Electric Arc**: An electric arc is struck between the electrodes. This arc generates intense heat.

4. **Vaporization of Metal**: The heat produced by the electric arc causes the metal at the electrodes to vaporize. This is a key step in forming colloidal particles.

5. **Condensation to Colloidal Size**: After vaporization, the metal vapor condenses into tiny particles that fall within the colloidal size range. These particles are what constitute the colloidal solution.

6. **Metals Used**: The Bredig's arc method is particularly effective for preparing colloidal solutions of certain metals, notably gold, silver, and platinum.

7. **Conclusion**: Therefore, the colloidal solutions prepared using Bredig's arc method are primarily of metals like gold, silver, and platinum.

**Final Answer**: Bredig's arc method is used for the preparation of colloidal solutions of metals such as gold, silver, and platinum.

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