Question

The number of S–S bond(s) in tetrathionate ion is ..........

Hint:

All polythionates contain at least one S–S bond, usually between central sulfur atoms.

Answer 1

Correct Answer: 3

Step 1: Write the structure of tetrathionate ion.
Tetrathionate ion is S$_4$O$_6^{2-}$, and its structure contains a chain:
S–S–S–S with terminal atoms bonded to oxygen atoms.
Step 2: Identify S–S bonds.
There are three S–S linkages in the chain, but only the central S–S bond is a true single S–S bond. The outer S atoms also form S–O bonds.
However, based on oxidation state considerations and structural studies, tetrathionate contains exactly **one** S–S single bond (between the two central sulfur atoms).
Step 3: Conclusion.
Thus, tetrathionate ion contains one S–S bond.