Washing sodal is

Options

A. `Na_(2)CO_(3).10H_(2)O`
B. `Na_2CO_(3).H_(2)O`
C. `Na_(2)CO_(3).5H_(2)O`
D. `Na_(2)CO_(3)`

Answer

**Step-by-Step Solution:**

1. **Identify the Chemical Formula of Washing Soda:**
Washing soda is chemically known as sodium carbonate with the formula Na2CO3. However, when it is hydrated, it is represented as Na2CO3·10H2O, indicating that it contains ten water molecules.

2. **Understanding the Components:**
- **Sodium Carbonate (Na2CO3):** This is the anhydrous form of washing soda, which means it does not contain water.
- **Hydrated Form (Na2CO3·10H2O):** This is the form of washing soda that is commonly used, which includes water molecules in its structure.

3. **Different Forms of Sodium Carbonate:**
- **Calcined Soda:** This refers to anhydrous sodium carbonate (Na2CO3) which has been heated to remove water.
- **Soda Ash:** This is another name for anhydrous sodium carbonate (Na2CO3) and is used in various industrial applications.

4. **Conclusion:**
- Washing soda is specifically the hydrated form of sodium carbonate, which is Na2CO3·10H2O.
- The anhydrous form is referred to as soda ash or calcined soda.

**Final Answer:**
Washing soda is Na2CO3·10H2O (sodium carbonate decahydrate).

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