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

Explanation

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

### Step 1: Understand Temporary Hardness
Temporary hardness in water is primarily caused by the presence of bicarbonates of calcium and magnesium. These compounds dissolve in water and lead to hardness.

**Hint:** Remember that temporary hardness is associated with bicarbonates, which can be removed by boiling.

### Step 2: Identify the Compounds
The two main compounds responsible for temporary hardness are:
- Calcium bicarbonate (Ca(HCO₃)₂)
- Magnesium bicarbonate (Mg(HCO₃)₂)

**Hint:** Focus on the two common bicarbonates that contribute to temporary hardness.

### Step 3: Boiling the Water Sample
When the water containing these bicarbonates is boiled, the bicarbonates decompose. The reactions are as follows:
1. For magnesium bicarbonate:
\[ \text{Mg(HCO}_3\text{)}_2 \xrightarrow{\text{heat}} \text{Mg(OH)}_2 + \text{CO}_2 + \text{H}_2\text{O} \]
This shows that magnesium bicarbonate converts to magnesium hydroxide upon boiling.

2. For calcium bicarbonate:
\[ \text{Ca(HCO}_3\text{)}_2 \xrightarrow{\text{heat}} \text{CaCO}_3 + \text{CO}_2 + \text{H}_2\text{O} \]
This indicates that calcium bicarbonate converts to calcium carbonate upon boiling.

**Hint:** Look at the products formed when each bicarbonate is heated.

### Step 4: Identify Compound X and Compound Y
From the reactions:
- Compound X (the one causing temporary hardness) can be either magnesium bicarbonate or calcium bicarbonate. However, since the question specifies "compound X" and "compound Y," we focus on magnesium bicarbonate as the primary example of temporary hardness.
- Compound Y, the product formed after boiling, is magnesium hydroxide (Mg(OH)₂).

**Hint:** Identify which compound is being converted into which product when boiled.

### Conclusion
Thus, the compounds X and Y are:
- X: Magnesium bicarbonate (Mg(HCO₃)₂)
- Y: Magnesium hydroxide (Mg(OH)₂)

**Final Answer:** X and Y, respectively, are magnesium bicarbonate (Mg(HCO₃)₂) and magnesium hydroxide (Mg(OH)₂).