Temparary hardness may be removed from water adding.

Options

A. `CaCO_(3)`
B. `Ca(OH)_(2)`
C. `CaSO_(4)`
D. `HCl`

Answer

To solve the question regarding the removal of temporary hardness from water, let's break down the steps:

### Step-by-Step Solution:

1. **Understanding Temporary Hardness**:
- Temporary hardness in water is primarily caused by the presence of bicarbonates of calcium (Ca(HCO₃)₂) and magnesium (Mg(HCO₃)₂).

2. **Methods of Removal**:
- The two common methods to remove temporary hardness are:
- **Boiling**: When water is boiled, bicarbonates decompose to form carbonates, which precipitate out as solid calcium carbonate (CaCO₃) and magnesium carbonate (MgCO₃).
- **Adding Calcium Hydroxide (Ca(OH)₂)**: This is a more effective method known as Clarke's method.

3. **Chemical Reactions**:
- When calcium hydroxide is added to water containing bicarbonates, the following reactions occur:
- Calcium bicarbonate reacts with calcium hydroxide:
\[ Ca(HCO₃)₂ + Ca(OH)₂ \rightarrow 2CaCO₃ (s) + 2H₂O \]
- Magnesium bicarbonate reacts with calcium hydroxide:
\[ Mg(HCO₃)₂ + Ca(OH)₂ \rightarrow MgCO₃ (s) + CaCO₃ (s) + 2H₂O \]
- The products, calcium carbonate (CaCO₃) and magnesium carbonate (MgCO₃), precipitate out of the solution.

4. **Filtration**:
- The precipitated solids (CaCO₃ and MgCO₃) can then be removed from the water by filtration.

5. **Conclusion**:
- Therefore, the correct answer to the question is that temporary hardness may be removed from water by adding **Calcium Hydroxide (Ca(OH)₂)**.

### Final Answer:
Temporary hardness may be removed from water by adding **Calcium Hydroxide (Ca(OH)₂)**.

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