Basicity of orthophosphoric acid is

Options

A. 2
B. 3
C. 4
D. 5

Explanation

To determine the basicity of orthophosphoric acid (H₃PO₄), we need to analyze its structure and the number of ionizable hydrogen ions (H⁺) it can release. Here’s a step-by-step solution:

### Step 1: Identify the formula of orthophosphoric acid
Orthophosphoric acid has the chemical formula H₃PO₄.

### Step 2: Draw the structure of orthophosphoric acid
The structure of H₃PO₄ can be represented as follows:
- Phosphorus (P) is at the center.
- It is double-bonded to one oxygen (O).
- It has three hydroxyl groups (–OH) attached to it.

The structure can be depicted as:
```
O
||
HO-P-OH
|
HO-OH
```

### Step 3: Understand the concept of basicity
Basicity refers to the ability of an acid to donate protons (H⁺ ions). The more protons an acid can donate, the higher its basicity.

### Step 4: Determine the number of ionizable hydrogen ions
In orthophosphoric acid (H₃PO₄), there are three hydroxyl (–OH) groups. Each of these hydroxyl groups can release one proton (H⁺) upon ionization.

### Step 5: Calculate the basicity
Since there are three hydroxyl groups, orthophosphoric acid can release three protons. Therefore, the basicity of orthophosphoric acid is 3.

### Conclusion
The basicity of orthophosphoric acid (H₃PO₄) is 3.