which of the following statement is not true about the oil - in - water type emulsion ?

Options

A. Addition of small amount of water , no separate layer of water is formed
B. Addition of a small amount of oil soluble dye renders the entire emulsion coloured
C. Addition of oil results in the formation of two layers
D. Addition of a small amount of an electroyte increases the conductivity of the emulsion

Answer

To determine which statement is not true about oil-in-water type emulsions, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding Oil-in-Water Emulsions**:
- In an oil-in-water emulsion, oil droplets are dispersed in water. The water is the continuous phase, while the oil is the dispersed phase.

2. **Analyzing the Options**:
- **Option 1**: "Addition of a small amount of water, no separate layer of water is formed."
- This statement is true. In an oil-in-water emulsion, adding a small amount of water does not create a separate layer, as the water is part of the continuous phase.

- **Option 2**: "Addition of a small amount of oil-soluble dye renders the entire emulsion colored."
- This statement is **not true**. Since oil is the dispersed phase, an oil-soluble dye would not dissolve in the water phase of the emulsion. Therefore, it would not color the entire emulsion.

- **Option 3**: "Addition of oil results in the formation of two layers."
- This statement is true. If a significant amount of oil is added to an oil-in-water emulsion, it can lead to the formation of two layers: one for the oil and one for the water.

- **Option 4**: "Addition of a small amount of an electrolyte increases the conductivity of the emulsion."
- This statement is true. Adding an electrolyte can increase the conductivity of the emulsion by increasing the number of ions in the solution.

3. **Conclusion**:
- The statement that is not true about oil-in-water emulsions is **Option 2**: "Addition of a small amount of oil-soluble dye renders the entire emulsion colored."

### Final Answer:
The statement that is not true about the oil-in-water type emulsion is **Option 2**.

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