Question

The, Species that donot contain peroxide ions are:

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

Answer 1

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

Peroxides are formed only by Hydrogen, Alkali and Alkaline earth metals. Except lead all other elements are from the mentioned categories. In lead oxide, lead has an oxidation state of $+4$ and oxygen state of each oxygen atom is $-2$. A peroxide ion will have a charge of $-2$ giving each oxygen atom a charge of $-1$.

Hence $Pb{O}_2$ doesn't have peroxide ion.