Hydrated sodium aluminium silicate is called ______.

Explanation

**Step-by-Step Text Solution:**

1. **Identify the Chemical Compound**: The question asks for the name of a compound known as hydrated sodium aluminum silicate.

2. **Recall the Common Name**: Hydrated sodium aluminum silicate is commonly known as "zeolite."

3. **Understanding the Composition**: The chemical formula for hydrated sodium aluminum silicate can be represented as Na2O.Al2O3.XSiO2, where 'X' indicates the number of water molecules associated with the silicate.

4. **Application of the Compound**: Zeolites, including hydrated sodium aluminum silicate, are used in various applications, one of which is to remove hardness from water.

5. **Final Answer**: Therefore, the answer to the question is "zeolite."

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