Each oxy-acid contains at least one X-OH unit (X is non-metal). The H-atom of X-OH unit is ionisable and the number of -OH groups directly attach to non-metal decides the basicity of oxy-acid.
Q. Which of the following oxy-acid does not have its peroxy form having two central atoms?

Options

A. `H_(2)SO_(4)`
B. `HNO_(3)`
C. `H_(3)PO_(4)`
D. none

Explanation

To solve the problem of identifying which oxy-acid does not have its peroxy form with two central atoms, we need to analyze the given oxy-acids based on their ability to form peroxy compounds. Here's a step-by-step solution:

### Step 1: Understand the Concept of Peroxy Compounds
Peroxy compounds are formed when an oxygen-oxygen bond is present in the structure, typically represented as -O-O-. For an oxy-acid to form a peroxy compound, it must have a central atom that can expand its octet, allowing for the formation of additional bonds.

### Step 2: Analyze Each Given Oxy-Acid
We will examine each of the given oxy-acids to determine if they can form a peroxy compound with two central atoms.

1. **H2SO4 (Sulfuric Acid)**
- Central Atom: Sulfur (S)
- Period: 3
- Ability to Expand Octet: Yes (can form peroxy linkage)
- Peroxy Form: H4S2O9 (contains two central atoms)

2. **HNO3 (Nitric Acid)**
- Central Atom: Nitrogen (N)
- Period: 2
- Ability to Expand Octet: No (cannot form peroxy linkage)
- Peroxy Form: Does not exist (no two central atoms)

3. **H3PO4 (Phosphoric Acid)**
- Central Atom: Phosphorus (P)
- Period: 3
- Ability to Expand Octet: Yes (can form peroxy linkage)
- Peroxy Form: H6P2O9 (contains two central atoms)

### Step 3: Conclusion
Based on the analysis:
- **H2SO4** and **H3PO4** can form peroxy compounds with two central atoms.
- **HNO3** cannot form a peroxy compound due to the inability of nitrogen to expand its octet.

Thus, the oxy-acid that does not have its peroxy form with two central atoms is **HNO3**.

### Final Answer
**HNO3** (Nitric Acid) does not have its peroxy form having two central atoms.

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