$\mathrm{S}-\mathrm{S}$ bond is not present in

• A

  $\mathrm{S}_2 \mathrm{O}_4^{2-}$
• B

  $\mathrm{S}_2 \mathrm{O}_5^{2-}$
• C

  $\mathrm{S}_2 \mathrm{O}_3^{2-}$
• Correct answer
  D

  $\mathrm{S}_2 \mathrm{O}_7^{2-}$

Solution

$\mathrm{S}_2 \mathrm{O}_7^{2-}$ has $\mathrm{S}-\mathrm{O}-\mathrm{S}$ bond.

Hence, the correct answer is option: 'D'.