Question

Which one of the following compounds is peroxide?
A.$N{O_2}$
B.$K{O_2}$
C.$Ba{O_2}$
D.$Mn{O_2}$

Answer 1

Peroxide is a chemical compound in which 2 oxygen atoms are linked together by a single covalent bond. The oxidation state of O is -1 in Peroxides. The compound reacts with dilute acid which gives ${H_2}{O_2}$ and has peroxide linkage.

Complete step by step answer: $Ba{O_2}$ has peroxide linkage because in this compound two oxygen atoms are linked by a single covalent bond. It is a very weak acid hydrogen peroxide which contains negatively charged peroxide ion $\left( {0_2^{2 - }} \right)$ in inorganic compounds. Some other examples of peroxide compounds are sodium peroxide which is used as a bleaching agent.
In $K{O_2}$, Oxidation state of oxygen is -1/2. Thus, it is superoxide. In $N{O_2}$ and $Mn{O_2}$, the oxidation state of O is -2 because Mn and N show variable oxidation states. In $Ba{O_2}$, the oxidation state of O is -1. Thus, it is a peroxide compound.
Hence, option C is correct.

Additional information:
Peroxide compounds are divided into 2 categories:
The first category is represented by cumene hydroperoxide. It is an organic compound used as a polymerization initiator. It is used as a source of acetone and phenol and in the inorganic compound, it is used as an oxidizing agent.
The second category is represented by ammonium peroxydisulfate and di-tert-butyl peroxide. Both these are used as initiators.

Note: There is a trick to find whether it is peroxide or not. Remember it if O is with metals of main group elements then, it is a peroxide compound but if O is attached with non-metals or other metal (except main metals) then, the compound is considered as oxide.