Washing soda is `Na_(2)CO_(3).xH_(2)O`. The value of `"x"` is __________

Answer

To determine the value of "x" in the formula for washing soda, which is represented as Na₂CO₃·xH₂O, we need to know the correct number of water molecules associated with washing soda.

### Step-by-Step Solution:

1. **Identify the Chemical Formula**:
- The chemical formula for washing soda is given as Na₂CO₃·xH₂O. Here, Na₂CO₃ represents sodium carbonate, and xH₂O represents the water of crystallization.

2. **Know the Common Hydrate Form**:
- The common hydrate form of washing soda is sodium carbonate decahydrate, which is Na₂CO₃·10H₂O. This means that for every formula unit of sodium carbonate, there are 10 water molecules associated with it.

3. **Set Up the Equation**:
- From the common knowledge of washing soda, we can equate x to the number of water molecules in the hydrate form. Therefore, we can write:
\[ x = 10 \]

4. **Conclusion**:
- Thus, the value of x in the formula Na₂CO₃·xH₂O is 10.

### Final Answer:
The value of "x" is **10**.