Question

How many of the following are mixed oxides?
$Pb_{3}O_{4},KO_{2},H_{2}O_{2},Al_{2}O_{3},Fe_{3}O_{4},N_{2}O,Mn_{3}O_{4}$

Answer 1

Mixed oxides are formed from two simple oxides.
$\left(Pb\right)_{3}O_{4}\left(2 PbO + \left(PbO\right)_{2}\right)$
$\left(Fe\right)_{3}O_{4}\left(FeO + \left(Fe\right)_{2} O_{3}\right)$
$\left(Mn\right)_{3}O_{4}\left(\left(MnO\right)_{2} + 2 MnO\right)$