Which of the following is not a true peroxide?

Options

A. `BaO_(2)`
B. `MnO_(2)`
C. `PbO_(2)`
D. Both (2) and (3)

Answer

4

Explanation

They are dioxides.There are covalent matallic oxides which decompose when heated giving the basic oxide and oxygen.`(2PbO_(2)rarr2PbO+O_(2))`.They are oxidizing agents but they do not yield hydrogen peroxide solution when acidified and therefore should not be called peroxides. They evolve `Cl_(2)` with conc. `HCl` and `O_(2)` with conc `H_(2)SO_(4)`
`MnO_(2)+4HClrarrMnCl_(2)+2H_(2)O+Cl_(2)uparrow`
`MnO_(2)+2H_(2)SO_(4)rarr2MnSO_(4)+O_(2)+2H_(2)O`
On the other hand ,`BaO_(2)`is a peroxide like`Na_(2)O_(3)`.These ionic compounds contain the peroxide ion`(O-O)^(2-)`.They all give hydrogen peroxide solution when treated with dilute acids:
`Na_(2)O_(2)+H_(2)SO_(4)rarrNa_(2)SO_(4)+H_(2)O_(2)`