Question

There is no $SS$ bond in:

• A. $S_2{O}_4^{2-}$
• B. $S_2{O}_5^{2-}$
• C. $S_2{O}_3^{2-}$
• D. $S_2{O}_7^{2-}$

Answer 1

Answer: (D)

in $S_2{O}_7^{2-}$ ion the two sulphur atoms are linked through an oxygen atom. Each sulphur atom is further linked with oxygen atoms. Its structure is: ${}^{-}O-\underset{\begin{array}{c}||\\ O\end{array}}{\stackrel{\begin{array}{c}O\\ ||\end{array}}{S}}-O-\underset{\begin{array}{c}||\\ O\end{array}}{\stackrel{\begin{array}{c}O\\ ||\end{array}}{S}}-O^{-}$ In all other ions $SS$ bond is present $S_2{O}_4^{2-}ion{\to }^{-}O-\stackrel{\begin{array}{c}O\\ ||\end{array}}{S}-\stackrel{\begin{array}{c}O\\ ||\end{array}}{S}-O^{-}$ $S_2{O}_5^{2-}ion{\to }^{-}O-\underset{\begin{array}{c}||\\ O\end{array}}{\stackrel{\begin{array}{c}O\\ ||\end{array}}{S}}-O-\stackrel{\begin{array}{c}O\\ ||\end{array}}{S}-O^{-}$ $S_2{O}_3^{2-}ion{\to }^{-}O-\underset{\begin{array}{c}||\\ O\end{array}}{\stackrel{\begin{array}{c}O\\ ||\end{array}}{S}}-O^{-}$