Which of the following can be used to determine the charge on the sol?

Options

A. Dialysis
B. Peptization
C. Electrophoresis
D. Osmosis

Answer

To determine the charge on a sol, we can analyze the given options step by step:

### Step 1: Understanding Dialysis
- **Explanation**: Dialysis is a process used to separate colloidal particles from smaller particles (crystalloids) using a semi-permeable membrane. In this process, colloidal particles cannot pass through the membrane, while ions can.
- **Conclusion**: Since dialysis does not provide information about the charge of the colloidal particles, it cannot be used to determine the charge on the sol.

### Step 2: Understanding Peptization
- **Explanation**: Peptization refers to the process of converting a precipitate into a colloidal form by adding a suitable electrolyte. The electrolytes used in this process are known as peptizing agents.
- **Conclusion**: Peptization does not directly indicate the charge of the colloidal particles, so it is not a suitable method for determining the charge on the sol.

### Step 3: Understanding Electrophoresis
- **Explanation**: Electrophoresis is the movement of colloidal particles under the influence of an electric field. In this method, a U-tube setup with two electrodes is used. When an electric current is passed through the sol, the particles migrate towards the electrode of opposite charge.
- If the colloidal particles move towards the positive electrode, they are negatively charged.
- Conversely, if they move towards the negative electrode, they are positively charged.
- **Conclusion**: Electrophoresis is a reliable method to determine the charge on the sol, as it directly observes the movement of particles in an electric field.

### Step 4: Understanding Osmosis
- **Explanation**: Osmosis is the movement of solvent molecules from a region of lower solute concentration to a region of higher solute concentration through a semi-permeable membrane.
- **Conclusion**: Osmosis does not provide any information about the charge of colloidal particles, making it an unsuitable method for this purpose.

### Final Answer
Based on the analysis of the options, the correct answer is **Electrophoresis** (Option 3), as it can be used to determine the charge on the sol.

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