Shape of `H_3PO_4` is

Options

A. Pyramidal
B. Tetrahedral
C. See-saw
D. Square planar

Answer

To determine the shape of phosphoric acid (H₃PO₄), we can follow these steps:

### Step 1: Identify the central atom
The central atom in H₃PO₄ is phosphorus (P).

### Step 2: Draw the Lewis structure
To draw the Lewis structure:
- Phosphorus (P) is the central atom.
- It is bonded to four oxygen (O) atoms: three of these are single-bonded to hydrogen (H) atoms, and one is double-bonded to phosphorus.
- The structure can be represented as:
- O
||
H-O-P-O-H
|
O-H

### Step 3: Count the number of sigma bonds and lone pairs
- Count the sigma bonds:
- There are 4 sigma bonds (3 P-O single bonds and 1 P=O double bond).
- Count the lone pairs:
- There are no lone pairs on the phosphorus atom.

### Step 4: Calculate the steric number
The steric number is calculated as:
\[ \text{Steric Number} = \text{Number of Sigma Bonds} + \text{Number of Lone Pairs} \]
\[ \text{Steric Number} = 4 + 0 = 4 \]

### Step 5: Determine the hybridization
With a steric number of 4, the hybridization of phosphorus is \( sp^3 \).

### Step 6: Determine the shape
For \( sp^3 \) hybridization, the geometry is tetrahedral. However, due to the presence of three hydrogen atoms and one double-bonded oxygen, the actual shape of H₃PO₄ is trigonal pyramidal.

### Conclusion
The shape of H₃PO₄ is trigonal pyramidal.

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