Answer the following :
Give the formula of Zeolite used in ion exchange method to remove permanent hardness of water.

Answer

To answer the question regarding the formula of zeolite used in the ion exchange method to remove permanent hardness of water, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Type of Zeolite**:
- Zeolites are a group of hydrated aluminosilicate minerals that can exchange ions. They are commonly used in water treatment processes.

2. **Determine the Specific Zeolite for Water Treatment**:
- The specific zeolite used for removing permanent hardness from water is sodium aluminum silicate.

3. **Write the Chemical Formula**:
- The chemical formula for the zeolite used in the ion exchange method is Na₂Al₂Si₂O₈·xH₂O, where "x" represents the number of water molecules associated with the zeolite.

4. **Explain the Ion Exchange Process**:
- In the ion exchange process, sodium ions (Na⁺) in the zeolite are exchanged for calcium (Ca²⁺) and magnesium (Mg²⁺) ions present in hard water. This exchange helps in softening the water.

### Final Answer:
The formula of zeolite used in the ion exchange method to remove permanent hardness of water is **Na₂Al₂Si₂O₈·xH₂O** (sodium aluminum silicate).

---