The true statement for the acids of phosphorus, `H_(3)PO_(2), H_(3)PO_(3) and H_(3)PO_(4)` is

Options

A. the order of their acidity is `H_(3)PO_(4)gtH_(3)PO_(3)gtH_(3)PO_(2)`
B. all of them are reducing in nature
C. all of them are tribasic acids
D. the geometry of phosphorus is tetrahedral in all the three.

Answer

To analyze the true statement for the acids of phosphorus, \( H_3PO_2 \), \( H_3PO_3 \), and \( H_3PO_4 \), we can break down the information step by step.

### Step 1: Identify the Acids and Their Structures
- **Acid 1**: \( H_3PO_2 \) (Phosphorous acid)
- **Acid 2**: \( H_3PO_3 \) (Phosphonic acid)
- **Acid 3**: \( H_3PO_4 \) (Phosphoric acid)

### Step 2: Determine the Number of Ionizable Hydrogens
- **\( H_3PO_2 \)** has 1 ionizable hydrogen.
- **\( H_3PO_3 \)** has 2 ionizable hydrogens.
- **\( H_3PO_4 \)** has 3 ionizable hydrogens.

### Step 3: Order of Acidity
The general trend in acidity for these acids is:
- \( H_3PO_4 > H_3PO_3 > H_3PO_2 \)

This is because the more ionizable hydrogens an acid has, the stronger it tends to be, and the presence of more oxygen atoms increases the acidity due to better stabilization of the negative charge after deprotonation.

### Step 4: Nature of the Acids
- **Reducing Nature**: \( H_3PO_2 \) is a strong reducing agent, while \( H_3PO_3 \) and \( H_3PO_4 \) are weaker reducing agents. Therefore, not all of them are reducing in nature.

### Step 5: Basicity of the Acids
- **Basicity**: \( H_3PO_2 \) is monoprotic, \( H_3PO_3 \) is diprotic, and \( H_3PO_4 \) is triprotic. Hence, they are not all tribasic.

### Step 6: Geometry of Phosphorus
- The geometry of phosphorus in all three acids is tetrahedral due to \( sp^3 \) hybridization. This is true for all three acids.

### Conclusion
The true statement among the options provided is that the geometry of phosphorus is tetrahedral in all three acids.

### Final Answer
The correct option is: **The geometry of phosphorus is tetrahedral in all three acids.**

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