At times the solution of lime water appears milky. Comment.

Explanation

**Step-by-Step Solution:**

1. **Understanding Lime Water**: Lime water is an aqueous solution of calcium hydroxide (Ca(OH)₂). It is a clear and colorless solution when prepared.

2. **Reaction with Carbon Dioxide**: When carbon dioxide (CO₂) gas is introduced into lime water, a chemical reaction occurs. The carbon dioxide reacts with calcium hydroxide to form calcium carbonate (CaCO₃).

\[
\text{Ca(OH)}_2 (aq) + \text{CO}_2 (g) \rightarrow \text{CaCO}_3 (s) + \text{H}_2\text{O} (l)
...