Which of the following has water of crystallization?

Options

A. Potassium chloride
B. Sodium chloride
C. Sodium nitrate
D. Washing soda crystals

Answer

To determine which of the given compounds has water of crystallization, we can follow these steps:

### Step 1: Understand the concept of water of crystallization
Water of crystallization refers to the water molecules that are chemically bound to a compound in its crystalline form. These water molecules are part of the structure of the compound and are essential for maintaining its crystalline structure.

### Step 2: Analyze the given options
We have the following compounds to analyze:
1. Potassium chloride (KCl)
2. Sodium chloride (NaCl)
3. Sodium nitrate (NaNO3)
4. Washing soda (sodium carbonate) (Na2CO3·H2O)

### Step 3: Check the chemical formulas for water of crystallization
- **Potassium chloride (KCl)**: This compound does not have any water molecules in its formula; it is simply KCl.
- **Sodium chloride (NaCl)**: Similar to potassium chloride, sodium chloride is also a simple ionic compound without any water molecules; it is NaCl.
- **Sodium nitrate (NaNO3)**: This compound is also an ionic compound and does not contain any water molecules; it is NaNO3.
- **Washing soda (sodium carbonate) (Na2CO3·H2O)**: This compound contains water of crystallization, as indicated by the dot (·) followed by H2O. This means that for every formula unit of Na2CO3, there is one molecule of water associated with it.

### Step 4: Conclusion
From the analysis, we can conclude that the only compound that has water of crystallization is **Washing soda (Na2CO3·H2O)**.

### Final Answer
Washing soda (Na2CO3·H2O) has water of crystallization.