How many water of crystallization are there in washing soda?

Explanation

To determine how many water molecules of crystallization are present in washing soda, we can follow these steps:

### Step 1: Identify the Chemical Formula
The chemical formula for washing soda is given as \( \text{Na}_2\text{CO}_3 \cdot 10 \text{H}_2\text{O} \).

### Step 2: Count the Water of Crystallization
From the formula, we can see that there are 10 molecules of water (10 H2O) associated with each formula unit of washing soda.

...