Anhydride of pyrophosphoric acid is

Options

A. `P_(4)O_(6)`
B. `P_(4)O_(10)`
C. `P_(2)O_(4)`
D. `P_(2)O_(3)`

Answer

To determine the anhydride of pyrophosphoric acid, we need to follow these steps:

### Step 1: Identify the formula of pyrophosphoric acid
The formula for pyrophosphoric acid is given as H₄P₂O₇.

### Step 2: Understand what an anhydride is
An anhydride is formed by the removal of water (H₂O) from an acid. Therefore, to find the anhydride of pyrophosphoric acid, we need to remove water from its formula.

### Step 3: Remove water from the formula of pyrophosphoric acid
When we remove one molecule of water (H₂O) from H₄P₂O₇, we are left with the formula for the anhydride. The removal of H₂O from H₄P₂O₇ gives us:

H₄P₂O₇ - H₂O → H₄P₂O₆

However, we need to consider that pyrophosphoric acid can also be viewed as two phosphoric acid molecules (H₃PO₄) linked together, which gives us a total of 2 phosphorus atoms.

### Step 4: Determine the correct anhydride
The anhydride corresponding to pyrophosphoric acid is actually phosphorus pentoxide, which has the formula P₄O₁₀. This is because when two H₃PO₄ molecules combine and lose water, they form P₄O₁₀.

### Step 5: Conclusion
Thus, the anhydride of pyrophosphoric acid is P₄O₁₀.

### Final Answer
The anhydride of pyrophosphoric acid is **P₄O₁₀**.

---