Question

Which of the following compounds does not contain peroxy linkages :
$Ba{O}_2,H_{2}S{O}_5,H_2{S}_2{O}_3$,

• A. $H_{2}S{O}_5$
• B. $Ba{O}_2$
• C. $H_2{S}_2{O}_3$
• D. both (a) and (b)

Answer 1

The correct option is C $H_2{S}_2{O}_3$

The compound contains a peroxy linkage when:
Calculated oxidation state is more the maximum oxidation state possible.

First compound,
$Ba{O}_2$
Let oxidation state of $Ba$ be $x$.
$\Rightarrow x+2\times (-2)=0$
$\Rightarrow x=+4$
calcualted O.S.$=+4$.
while maximum O.S. possible for $Ba$ is +3. So, $Ba{O}_2$ contains a peroxy linkage.
The structure of $Ba{O}_2$,



Second compound,
$H_{2}S{O}_5$
Let oxidation state of $S$ be $x$.
$\Rightarrow x+2\times (+1)+5\times (-2)=0$
$\Rightarrow x=+8$
calcualted O.S.$=+8$.
while maximum O.S. possible for $S$ is +6. So, $H_{2}S{O}_5$ contains a peroxy linkage.
The structure of $H_{2}S{O}_5$,




Third compound,
$H_2{S}_2{O}_3$
Let oxidation state of $S$ be $x$.
$\Rightarrow 2x+2\times (+1)+3\times (-2)=0$
$\Rightarrow x=+2$
calcualted O.S.$=+2$.
while maximum O.S. possible for $S$ is +6. So, $H_2{S}_2{O}_3$ does not contains a peroxy linkage.
The structure of $H_2{S}_2{O}_3$,