Question

The species that does not contain peroxide ion is :

• A. $Pb{O}_2$
• B. $H_2{O}_2$
• C. $Sr{O}_2$
• D. $Ba{O}_2$

Answer 1

The correct option is A $Pb{O}_2$

Metallic oxides which on treatment with dilute acids produce hydrogen peroxide are called peroxides. All peroxides contain a peroxide ion $(O_2{)}^{2–}$having the structure $–O–O–$ . $Pb{O}_2$ does not contain a peroxide ion $(O_2{)}^{2-}$ and it can not be called as peroxides.

$Pb{O}_2$ contains $O^{2-}$ ions and Option (A) $Pb$ is $+4$, whereas (B), (C) and (D) contains $[O–O{]}^{2-}$ ions (peroxide ions). Thus Option A is correct.