Which one of the following compounds is a peroxide?

Step-by-step solution

Key Idea:- In peroxides, the oxidation state of O is - 1 and they give H ₂ O ₂ , with dilute acids, and have peroxide linkage. In KO ₂ , +1+( x 2)=0 x=- 1 2 (thus, it is a superoxide, not a peroxide.) In BaO ₂ , aligned & +2+( x 2)=0 & x =-1 aligned Thus, it is a peroxide. Only it gives H ₂ O ₂ when reacts with dilute acids and has peroxide linkage as aligned & Ba ²⁺[ O - O ]²⁻ & peroxide linkage aligned In MnO ₂ and NO ₂, Mn and N exhibit variable oxidation states, thus, the oxidation state of O in these is -2 . H