Fill in the following blanks with suitable words :
When carbon dioxide is passed through lime water. It turns milky due to the formation of ______.

Answer

To fill in the blank in the statement "When carbon dioxide is passed through lime water, it turns milky due to the formation of ______," we can follow these steps:

### Step-by-Step Solution:

1. **Identify Lime Water**: Understand that lime water is a solution of calcium hydroxide (Ca(OH)₂) in water.

2. **Introduce Carbon Dioxide**: When carbon dioxide (CO₂) gas is introduced into lime water, a chemical reaction occurs.

3. **Chemical Reaction**: The reaction between carbon dioxide and calcium hydroxide can be represented as:
\[ \text{Ca(OH)}_2 + \text{CO}_2 \rightarrow \text{CaCO}_3 + \text{H}_2\text{O} \]
In this reaction, calcium carbonate (CaCO₃) is formed along with water (H₂O).

4. **Observation of Milky Appearance**: Calcium carbonate is not soluble in water, and it precipitates out of the solution, giving the lime water a milky appearance.

5. **Conclusion**: Therefore, the blank can be filled with "calcium carbonate".

### Final Answer:
When carbon dioxide is passed through lime water, it turns milky due to the formation of **calcium carbonate**.

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