The exhausted permutit is generally regenerated by percolating through it a solution of

Options

A. sodium chloride
B. calcium chloride
C. magnesium chloride
D. barium chloride

Answer

To solve the question regarding the regeneration of exhausted permutit, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Permutit**:
- Permutit is a type of zeolite used in water softening. It works by exchanging sodium ions for calcium and magnesium ions in hard water.

2. **Identify Exhausted Permutit**:
- Exhausted permutit refers to the condition when it has already exchanged its sodium ions with calcium and magnesium ions from the hard water, thus becoming ineffective in softening water.

3. **Regeneration Process**:
- To regenerate exhausted permutit, we need to restore its sodium ion content. This is typically done by flushing it with a solution that contains a high concentration of sodium ions.

4. **Choosing the Right Solution**:
- The most common solution used for this purpose is a sodium chloride (NaCl) solution, often referred to as brine. This solution provides a sufficient concentration of sodium ions to replace the calcium and magnesium ions that have been absorbed by the permutit.

5. **Conclusion**:
- Therefore, the exhausted permutit is generally regenerated by percolating through it a solution of sodium chloride (NaCl).

### Final Answer:
The exhausted permutit is generally regenerated by percolating through it a solution of **sodium chloride (NaCl)**.

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