In which of the following acids, P-P bonds is present?

Options

A. Tetra poly phosphoric acid `(H_(6)P_(4)O_(13))`
B. Pyrophosphoric acid `(H_(4)P_(2)O_(7))`
C. Hypophosphoric acid `(H_(4)P_(2)O_(6))`
D. Polymetaphosphoric acid `(HPO_(3))_(pi)`

Answer

To determine which of the given acids contains a P-P bond, we will analyze each option step by step.

### Step 1: Identify the Acids
The acids given in the question are:
1. Tetrapolyphosphoric acid
2. Pyrophosphoric acid
3. Hypophosphoric acid
4. Polymetaphosphoric acid

### Step 2: Understand the Structure of Each Acid
- **Tetrapolyphosphoric acid**: This acid typically contains P-O-P linkages rather than P-P bonds. Its structure involves multiple phosphorus atoms linked by oxygen atoms.

- **Pyrophosphoric acid (H₄P₂O₇)**: This acid also contains P-O-P linkages. The structure consists of two phosphorus atoms connected by oxygen atoms, and it does not have a P-P bond.

- **Hypophosphoric acid**: This acid is known to have a P-P bond. The structure includes two phosphorus atoms directly bonded to each other (P-P), along with several hydroxyl (OH) groups and oxygen atoms.

- **Polymetaphosphoric acid**: This acid has a repeating unit structure and contains P-O-P linkages. It does not have a direct P-P bond.

### Step 3: Conclusion
From the analysis above, the acid that contains a P-P bond is **Hypophosphoric acid**.

### Final Answer
**Hypophosphoric acid contains a P-P bond.**

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