Gandhiji prepared salt from sea water in Dandi by the process

Options

A. decantation
B. sedimentation
C. evaporation
D. filtration

Explanation

To solve the question regarding how Gandhiji prepared salt from sea water in Dandi, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Composition of Sea Water**:
- Sea water is a mixture primarily composed of water and dissolved salts, predominantly sodium chloride (table salt).

2. **Identifying the Desired Product**:
- The goal is to extract salt from the sea water, which means we need to separate the salt from the water.

3. **Considering Separation Methods**:
- We need to evaluate the methods provided in the options:
- **Decantation**: This method involves pouring off a liquid to leave behind solids. It is not suitable here since we want to separate dissolved salt from water.
- **Sedimentation**: This involves letting particles settle at the bottom, which is not applicable for dissolved salts in water.
- **Evaporation**: This is the process where water is heated until it turns into vapor, leaving solid salt behind.
- **Filtration**: This method is used to separate solids from liquids, but since salt is dissolved, it cannot be filtered out.

4. **Choosing the Correct Method**:
- The most effective method to extract salt from sea water is evaporation. By allowing the water to evaporate, the salt remains as a solid residue.

5. **Conclusion**:
- Therefore, the correct answer to the question is **evaporation** (Option 3).

### Final Answer:
Gandhiji prepared salt from sea water in Dandi by the process of **evaporation**.

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