Which of the following processes can be used to remove both temporary and permanent hardness?

Options

A. Clark's method
B. Addition of washing soda
C. Boiling
D. All the above

Explanation

To solve the question "Which of the following processes can be used to remove both temporary and permanent hardness?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand Temporary and Permanent Hardness**:
- **Temporary Hardness**: This type of hardness is caused by the presence of bicarbonate salts (like calcium bicarbonate) in water. It can be removed by boiling the water.
- **Permanent Hardness**: This type is caused by the presence of chloride and sulfate salts (like calcium chloride and magnesium sulfate) in water. It cannot be removed by boiling.

2. **Analyze the Options**:
- **Option 1: Lime Method**: This method is effective for removing temporary hardness by converting bicarbonates into insoluble carbonates. However, it does not remove permanent hardness.
- **Option 2: Addition of Washing Soda**: Washing soda (sodium carbonate) can remove both temporary and permanent hardness by precipitating calcium and magnesium ions from the water.
- **Option 3: Boiling**: Boiling water removes only temporary hardness, as it precipitates bicarbonate salts but does not affect permanent hardness.
- **Option 4: All of These**: This option suggests that all the methods mentioned can remove both types of hardness, which is incorrect based on our analysis.

3. **Conclusion**:
- The only method that can remove both temporary and permanent hardness is the **addition of washing soda**. Therefore, the correct answer is **Option 2**.

### Final Answer:
The process that can be used to remove both temporary and permanent hardness is the **addition of washing soda**.

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