Question

Which of the following having S-O-S linkage-

• A. H$_2$S$_2$O$_5$
• B. H$_2$S$_2$O$_7$
• C. H$_2$S$_3$O$_6$
• D. H$_2$S$_2$O$_4$

Answer 1

Answer: (B)

H$_2$S$_2$O$_7$

Answer 2

To determine which of the given compounds has an S-O-S linkage, we need to analyze the molecular structure of each option.

1. H₂S₂O₅ (Disulfurous acid or Pyrosulfurous acid):
   The structure contains an S-O-S linkage: HO−S(=O)−O−S(=O)−OH

2. H₂S₂O₇ (Disulfuric acid or Pyrosulfuric acid):
   The structure contains an S-O-S linkage: HO−S(=O)₂−O−S(=O)₂−OH

3. H₂S₃O₆ (Trithionic acid):
   The structure contains an S-S-S linkage, not an S-O-S linkage: HO−S(=O)₂−S−S(=O)₂−OH

4. H₂S₂O₄ (Dithionous acid):
   The structure contains an S-S linkage, not an S-O-S linkage: HO−S(=O)−S(=O)−OH

Both H₂S₂O₅ and H₂S₂O₇ contain an S-O-S linkage. H₂S₂O₇ (pyrosulfuric acid) is a very well-known and stable compound with a definitive S-O-S linkage.