Question

Why is ${\mathrm{PbO}}_2$ not a peroxide?

Answer 1

Peroxide:

1. Peroxide refers to a group of chemical compounds in which two oxygen atoms are joined by a single covalent connection.
2. Peroxides are metallic oxides that contain hydrogen peroxide and are mixed with dilute acids.
3. The chemical formula of Hydrogen peroxide is ${\mathrm{H}}_2{\mathrm{O}}_2$.

Lead Oxide:

1. Because ${\mathrm{PbO}}_2$ (Lead oxide) does not contain peroxide ions, it should not be called peroxide.
2. $\mathrm{PbO}$ is significantly more stable than ${\mathrm{PbO}}_2$ as a result of the inert pair effect.
3. And we know that in $\mathrm{PbO}$, $\mathrm{Pb}$ is in an oxidation state of $+2$, and in ${\mathrm{PbO}}_2$, it is in an oxidation state of $+4$.
4. This is why, in order to achieve stability, ${\mathrm{PbO}}_2$ readily decomposes to $\mathrm{PbO}$.
5. Lead oxide is a metallic oxide that reacts with hydrochloric acid to form lead chloride and water, although it is not classified as a base since chlorine is not created.
6. Lead oxide, on the other hand, is not a base.

Hence, ${\mathrm{PbO}}_2$ is not a peroxide.