Addition of which substance hastens the process of sedimentation in water?

Options

A. Potash alum
B. Bleaching powder
C. Chlorine
D. Sand

Explanation

**Step-by-Step Solution:**

1. **Understanding Sedimentation**: Sedimentation is the process where solid particles settle down to the bottom of a liquid. This process is important for purifying water by removing impurities.

2. **Identifying the Substance**: The question asks which substance can hasten or speed up this process of sedimentation in water.

3. **Analyzing the Options**: The options provided are:
- Option 1: Potassium
- Option 2: Bleaching powder
- Option 3: Chlorine
- Option 4: Sand

4. **Correct Answer**: The correct answer is **Potash Alum** (though not listed in the options, it is implied as the substance that hastens sedimentation). Potash alum is a hydrated double sulfate salt of potassium and aluminum, with the chemical formula KAl(SO4)2·12H2O.

5. **How Potash Alum Works**: When potash alum is added to water, it helps in the process known as "loading." This process increases the rate of sedimentation by allowing insoluble solid particles to accumulate on the alum. As these particles cluster together, they become heavier and settle down more quickly.

6. **Conclusion**: Therefore, the addition of potash alum hastens the sedimentation process in water by promoting the aggregation of solid impurities, making it easier to remove them.

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