Among the following, the false statement is :

Options

A. It is possible to cause artificial rain by throwing electrified sand carrying charge opposite to the one on clouds from an aeroplane
B. Lyophilic sol can be coagulated by adding an electrolyte
C. Latex is a colloidal solution of rubber particles which are positively charged
D. Tyndall effect can be used to distinguish between a colloidal solution and true solution

Explanation

To determine the false statement among the given options, let's analyze each statement step by step.

### Step 1: Analyze the First Statement
**Statement:** It is possible to cause artificial rain by throwing electrified sand carrying charge opposite to the one on clouds from an airplane.

**Analysis:**
- Clouds consist of tiny water droplets that can carry a charge.
- If the clouds are negatively charged, throwing positively charged sand particles can attract these water droplets.
- The attraction of the water droplets to the sand particles can lead to the formation of larger droplets, which can eventually fall as rain.
- **Conclusion:** This statement is true.

### Step 2: Analyze the Second Statement
**Statement:** Lyophilic salts can be coagulated by adding an electrolyte.

**Analysis:**
- Lyophilic colloids are stable and can be coagulated by adding an electrolyte.
- The addition of an electrolyte can neutralize the charge on the colloidal particles, leading to coagulation.
- **Conclusion:** This statement is true.

### Step 3: Analyze the Third Statement
**Statement:** Latex is a colloidal solution of rubber particles which are positively charged.

**Analysis:**
- Latex is indeed a colloidal solution of rubber particles.
- However, rubber particles in latex are negatively charged, not positively charged.
- This is a critical error in the statement.
- **Conclusion:** This statement is false.

### Step 4: Analyze the Fourth Statement
**Statement:** Tyndall effect can be used to distinguish between colloidal solution and true solution.

**Analysis:**
- The Tyndall effect is the scattering of light by particles in a colloid.
- Colloidal particles are large enough to scatter light, while true solutions do not scatter light due to their smaller particle size.
- Therefore, the Tyndall effect can indeed be used to differentiate between colloidal solutions and true solutions.
- **Conclusion:** This statement is true.

### Final Conclusion
After analyzing all the statements, the false statement is the third one: "Latex is a colloidal solution of rubber particles which are positively charged." The correct information is that rubber particles in latex are negatively charged.

### Answer:
The false statement is the third one.

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