select incorrect statement:

Options

A. Micelles are associated collodies
B. the electrical charge on a colloid paritcle is indicated by electrophoresis
C. formation of micelles takes place above Kraft temperature
D. formation of micells takes place below CMC.

Answer

To solve the question of selecting the incorrect statement regarding colloids and micelles, we will analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Micelles and CMC**:
- Micelles are aggregates of surfactant molecules that form in a solution when the concentration of the surfactant exceeds a certain threshold known as the Critical Micelle Concentration (CMC).
- Above the CMC, surfactants can form micelles, which are important in various applications such as detergents and emulsifiers.

2. **Evaluating the First Statement**:
- **Statement**: "Micelles are associated colloids."
- **Analysis**: This statement is true. Micelles are indeed a type of associated colloid that forms when surfactants exceed the CMC.

3. **Evaluating the Second Statement**:
- **Statement**: "The electric charge on a colloid particle is indicated by electrophoresis."
- **Analysis**: This statement is also true. Electrophoresis is a technique used to determine the charge of colloidal particles by observing their movement in an electric field.

4. **Evaluating the Third Statement**:
- **Statement**: "Formation of micelles takes place above Kraft temperature."
- **Analysis**: This statement is true. The formation of micelles occurs above the Kraft temperature, which is the temperature above which micelles can form.

5. **Evaluating the Fourth Statement**:
- **Statement**: "Formation of micelles takes place below CMC."
- **Analysis**: This statement is incorrect. Micelles do not form below the CMC; they only form when the concentration of surfactants is above the CMC.

### Conclusion:
The incorrect statement among the options provided is: **"Formation of micelles takes place below CMC."**