Why hair washed with hard water look dull ?

Explanation

**Step-by-Step Solution:**

1. **Understanding Hard Water Composition**: Hard water contains high concentrations of minerals, primarily calcium (Ca²⁺) and magnesium (Mg²⁺) ions.

2. **Interaction with Soap/Shampoo**: When we wash our hair with soap or shampoo in hard water, the calcium and magnesium ions react with the soap. This reaction leads to the formation of insoluble compounds.

3. **Formation of Precipitate**: For example, when magnesium chloride (MgCl₂) is present in hard water, it reacts with the soap to form an insoluble white precipitate. This precipitate is a result of the soap molecules binding with the calcium and magnesium ions.

...