An emulsion cannot be broken by ……….and …….. .

Options

A. heating
B. adding more amount of dispersion medium
C. freezing
D. adding emulsifying agent

Explanation

To answer the question "An emulsion cannot be broken by ……….and ……..", we need to understand the nature of emulsions and the factors that can affect their stability.

### Step-by-Step Solution:

1. **Understanding Emulsions**:
- An emulsion is a colloidal system consisting of two immiscible liquids, where one liquid is dispersed in the other. Common examples include oil in water (O/W) and water in oil (W/O).

2. **Factors Affecting Emulsion Stability**:
- Emulsions can be broken or destabilized by various means, such as heating, freezing, or centrifugation. However, certain actions can stabilize or maintain the emulsion.

3. **Identifying Stabilizing Factors**:
- **Adding More Dispersion Medium**: When more of the dispersion medium (the continuous phase) is added, it dilutes the emulsion but does not break it. This is because the emulsion remains a colloidal system.
- **Adding an Emulsifying Agent**: An emulsifying agent (or emulsifier) helps to stabilize the emulsion by reducing the surface tension between the two immiscible liquids. This addition does not break the emulsion but rather makes it more stable.

4. **Conclusion**:
- Therefore, the two factors by which an emulsion cannot be broken are:
- **Adding more dispersion medium**
- **Adding an emulsifying agent**

### Final Answer:
An emulsion cannot be broken by **adding more dispersion medium** and **adding an emulsifying agent**.