Anhydride of orthophosphoric acid is

Options

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

Answer

To determine the anhydride of orthophosphoric acid, we can follow these steps:

### Step 1: Identify the formula of orthophosphoric acid
Orthophosphoric acid is represented by the chemical formula H₃PO₄.

### Step 2: Understand what an anhydride is
An anhydride is formed when water molecules are removed from an acid. In this case, we need to remove water from orthophosphoric acid (H₃PO₄).

### Step 3: Calculate the number of water molecules to be removed
For orthophosphoric acid (H₃PO₄), we can remove three water molecules (H₂O) to form its anhydride.

### Step 4: Write the reaction for the formation of the anhydride
Removing three water molecules from H₃PO₄ gives us:
\[ H₃PO₄ - 3H₂O \rightarrow P₂O₅ \]

### Step 5: Identify the correct anhydride
The compound P₂O₅ is known as phosphorus pentoxide. However, it can also exist in a dimeric form as P₄O₁₀. Therefore, the anhydride of orthophosphoric acid can be represented as P₄O₁₀.

### Conclusion
The anhydride of orthophosphoric acid is P₄O₁₀.

### Final Answer
**P₄O₁₀**

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