The temporary hardness of a water sample is due to compound X. Boiling this sample converts X to compound Y. X and Y, respectively, are :

Options

A. `Mg(HCO_(3))_(2)` and `MgCO_(3)`
B. `Ca(HO_(3))_(2)` and CaO
C. `Ca(HCO_(3))_(2)` and `Ca(OH)_(2)`
D. `Mg(HCO_(3))_(2)` and `Mg(OH)_(2)`

Answer

To solve the question regarding the temporary hardness of a water sample and the compounds involved, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Temporary Hardness**:
- Temporary hardness in water is primarily caused by the presence of bicarbonates of calcium and magnesium. These bicarbonates dissolve in water and contribute to hardness.

2. **Identify Compound X**:
- The question states that the temporary hardness is due to compound X. Since we are dealing with temporary hardness, we can deduce that compound X is likely a bicarbonate of either calcium or magnesium.

3. **Boiling the Water**:
- When water containing bicarbonates is boiled, the bicarbonates decompose. This process converts the soluble bicarbonates into insoluble carbonates, which precipitate out of the solution.

4. **Identify Compound Y**:
- Upon boiling, magnesium bicarbonate (Mg(HCO₃)₂) decomposes to form magnesium carbonate (MgCO₃), which is insoluble in water. Therefore, compound Y is magnesium carbonate.

5. **Conclusion**:
- Based on the above reasoning, we conclude that:
- Compound X is Magnesium Bicarbonate (Mg(HCO₃)₂).
- Compound Y is Magnesium Carbonate (MgCO₃).

### Final Answer:
- X and Y, respectively, are: **Magnesium Bicarbonate and Magnesium Carbonate**.