Which of the following does not contain a symmetrical structure ? 

Options

A. `H_(2)S_(2)O_(4)`
B. `H_(2)S_(2)O_(5)`
C. `H_(2)S_(2)O_(7)`
D. `H_(2)S_(2)O_(6)`

Answer

To determine which of the given compounds does not contain a symmetrical structure, we will analyze the structures of the oxyacids of sulfur provided in the question: H2S2O4, H2S2O5, H2S2O6, and H2S2O7.

### Step 1: Identify the Compounds
The compounds given are:
1. H2S2O4 (Diethinus acid)
2. H2S2O5 (Disulfurous acid)
3. H2S2O6 (Diethinic acid)
4. H2S2O7 (Pyrosulfuric acid or Disulfuric acid)

### Step 2: Draw the Structures
- **H2S2O4**: This compound has a structure with a sulfur-sulfur bond, where each sulfur atom is bonded to one double-bonded oxygen and one hydroxyl (OH) group. The structure can be visualized as symmetrical.

- **H2S2O5**: This compound also has a sulfur-sulfur bond, with each sulfur atom bonded to one double-bonded oxygen and one hydroxyl group. However, the presence of an additional oxygen atom in the structure leads to asymmetry.

- **H2S2O6**: Similar to H2S2O4, H2S2O6 has a sulfur-sulfur bond with each sulfur atom bonded to two double-bonded oxygens and one hydroxyl group. This structure is symmetrical.

- **H2S2O7**: This compound has a sulfur-sulfur bond as well, with each sulfur atom bonded to two double-bonded oxygens and one hydroxyl group. This structure is also symmetrical.

### Step 3: Analyze Symmetry
- **H2S2O4**: Symmetrical
- **H2S2O5**: Asymmetrical due to the extra oxygen
- **H2S2O6**: Symmetrical
- **H2S2O7**: Symmetrical

### Conclusion
The compounds that do not contain a symmetrical structure are **H2S2O5** and **H2S2O7**.

### Final Answer
The compound that does not contain a symmetrical structure is **H2S2O5**.

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