Which of the following compounds may have a `P-P` bond :

Options

A. `H_(4)P_(2)O_(5)`
B. `(HPO_(3))_(3)`
C. `H_(4)P_(2)O_(7)`
D. `H_(4)P_(2)O_(6)`

Explanation

To determine which of the given compounds may have a P-P bond, we will analyze each compound's structure step by step.

### Step 1: Analyze Compound A - H4P2O5
1. **Count the Atoms**: The formula indicates there are 2 phosphorus (P) atoms, 4 hydrogen (H) atoms, and 5 oxygen (O) atoms.
2. **Draw the Structure**: The structure can be drawn with two phosphorus atoms connected by oxygen atoms and hydrogen atoms attached to phosphorus.
3. **Check for P-P Bond**: In this structure, we find that there is no direct P-P bond; instead, there is a P-O-P linkage.

**Hint for Step 1**: Look for direct connections between phosphorus atoms in the structure.

### Step 2: Analyze Compound B - HPO3 (thrice)
1. **Count the Atoms**: The formula indicates there is 1 phosphorus atom and 3 oxygen atoms in a cyclic arrangement.
2. **Draw the Structure**: The cyclic structure shows phosphorus bonded to three oxygen atoms.
3. **Check for P-P Bond**: There are no P-P bonds present; only P-O bonds are observed.

**Hint for Step 2**: Identify if the phosphorus is part of a cyclic structure and how it connects to oxygen.

### Step 3: Analyze Compound C - H4P2O7
1. **Count the Atoms**: The formula indicates there are 2 phosphorus atoms, 4 hydrogen atoms, and 7 oxygen atoms.
2. **Draw the Structure**: The structure can be drawn with two phosphorus atoms, connected through oxygen atoms and surrounded by hydrogen.
3. **Check for P-P Bond**: In this structure, there is no direct P-P bond; only P-O bonds are present.

**Hint for Step 3**: Ensure to visualize the connectivity between phosphorus and oxygen atoms clearly.

### Step 4: Analyze Compound D - H4P2O6
1. **Count the Atoms**: The formula indicates there are 2 phosphorus atoms, 4 hydrogen atoms, and 6 oxygen atoms.
2. **Draw the Structure**: The structure can be drawn with two phosphorus atoms directly connected to each other, along with oxygen and hydrogen atoms.
3. **Check for P-P Bond**: In this structure, there is a direct P-P bond present, along with P-O bonds.

**Hint for Step 4**: Look for direct connections between phosphorus atoms without intermediaries like oxygen.

### Conclusion
After analyzing all four compounds, we find that only **H4P2O6** contains a P-P bond. Therefore, the correct answer is **D - H4P2O6**.