# What are the oxidation numbers of SO_2, SO_3, P_2O_3, and P_2O_5? What is the oxidation number of hydrogen peroxide?

Sep 13, 2017

Well, we can assign oxidation numbers........

#### Explanation:

And for oxides, the oxygen state of the oxygen is necessarily $- I I$.. And we assign the oxidation state of the heteroatom on this basis....

$S {O}_{2}$, we gots $S \left(+ I V\right)$;

$S {O}_{3}$, we gots $S \left(+ V I\right)$;

${P}_{2} {O}_{3}$, we gots $P \left(+ I I I\right)$;

And for ${P}_{2} {O}_{5}$, we gots $P \left(+ V\right)$......

Sometimes we consider a $\text{peroxide}$, i.e. a $O - O$ linkage; here the electrons in the (weak) $O - O$ bond are assigned to each element (because the oxygens HAVE EQUAL electronegativity) to give say the hydroperoxyl radical:

${H}_{2} {O}_{2} \rightarrow 2 \times \dot{O} H$

When we do this for $O {F}_{2}$...we get $2 \times {F}^{-} + O \left(+ I I\right)$

What are the individual oxidation states of the oxygen atoms in the ozone molecule, $O = \stackrel{+}{O} - {O}^{-}$?