Question

Which one among the following has the "S-O-S" bonding?

• A. \(H_2S_2O_5\)
• B. \(H_2S_2O_8\)
• C. \(H_2S_2O_7\)
• D. \(H_2S_2O_4\)

Hint:

Pyro acids are formed by condensation of two oxyacids with loss of water. Pyrosulfuric acid \((H_2S_2O_7)\) contains the characteristic \(S-O-S\) bridge.

Answer 1

The Correct Option is C

Step 1: Recognize oleum's distinctive bridge.
H₂S₂O₇ is produced by dehydrating 2H₂SO₄ molecules, linking them via an oxygen atom to give an S–O–S bridge. H₂S₂O₈ instead has a peroxide –O–O– link; the other two options lack the S–O–S feature.

Step 2: Final Answer:
H₂S₂O₇ (option 3).