Which of the following will show Tyndall effect?

Options

A. Aqueous solution of soap below critical micelle concentration
B. Aqueous solution of soap above critical micelle concentration
C. Aqueous solution of sodium chloride
D. Aqueous solution of sugar

Explanation

To determine which of the given options will show the Tyndall effect, we need to understand what the Tyndall effect is and the nature of the solutions provided in the options.

### Step-by-Step Solution:

1. **Understanding Tyndall Effect**:
- The Tyndall effect is the scattering of light by particles in a colloid. For a solution to exhibit the Tyndall effect, it must contain colloidal particles.

2. **Identifying the Nature of Solutions**:
- We need to analyze each option to see if it is a colloidal solution or not.

3. **Option Analysis**:
- **Option A: Aqueous solution of soap below critical micelle concentration (CMC)**:
- Below CMC, soap molecules do not form micelles and behave as a strong electrolyte solution. Strong electrolytes do not scatter light significantly, hence this will not show the Tyndall effect.

- **Option B: Aqueous solution of soap above critical micelle concentration (CMC)**:
- Above CMC, soap molecules aggregate to form micelles, leading to the formation of a colloidal solution. Colloidal solutions can scatter light, thus this option will show the Tyndall effect.

- **Option C: Aqueous solution of sodium chloride**:
- Sodium chloride in water dissociates into ions, forming a true solution. True solutions do not scatter light, so this will not show the Tyndall effect.

- **Option D: Aqueous solution of sugar**:
- Similar to sodium chloride, sugar dissolves in water to form a true solution. True solutions do not exhibit the Tyndall effect.

4. **Conclusion**:
- Among the options analyzed, only the aqueous solution of soap above the critical micelle concentration is a colloidal solution that can show the Tyndall effect.

### Final Answer:
- The correct option that shows the Tyndall effect is **Option B: Aqueous solution of soap above critical micelle concentration**.