Rekha's mother adds phitkari (alum) to water collected from the pond every day in order to

Options

A. decolourise water
B. sediment light suspended Impurities
C. change hard water Into soft water
D. kill germs in water

Answer

### Step-by-Step Solution:

1. **Identify the Substance**: Rekha's mother adds phitkari, which is commonly known as alum. The chemical name for alum is Aluminium Sulphate.

2. **Understand the Purpose**: The primary reason for adding alum to water is to improve its quality. Alum is used in water treatment processes.

3. **Removal of Impurities**: When alum is added to water, it helps in the coagulation process. This means that it causes tiny particles and impurities in the water to clump together and form larger particles, which can then settle down.

4. **Decolorization and Turbidity**: By clumping together, these impurities can be removed from the water, thus helping to decolorize it if it has any color. Additionally, it helps in reducing turbidity, which refers to the cloudiness or haziness of the water caused by large numbers of individual particles.

5. **Conclusion**: Therefore, the main purpose of adding alum to pond water is to decolorize the water and remove turbidity, making it clearer and safer for use.

### Final Answer:
Rekha's mother adds phitkari (alum) to water collected from the pond every day in order to decolorize the water and remove turbidity.