How many water molecules of crystallisation are present in
(a) trona, (b) borax and (c ) carnallite ?

Explanation

To determine the number of water molecules of crystallization present in trona, borax, and carnallite, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Chemical Formula of Trona**:
- The chemical formula for trona is \( \text{Na}_2\text{CO}_3 \cdot \text{NaHCO}_3 \cdot 2\text{H}_2\text{O} \).
- From the formula, we can see that there are **2 water molecules** of crystallization.

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