The oxidation number of carbon in $CH_2O$ is

The average oxidation state of sulphur in $Na_2S_2O_3$ is:

Write the oxidation number of oxygen in $KO_{3}$ and $Na_{2}O_{2}$.

What is the oxidation number of $P$ in $KH_2PO_2$?

In the following reaction,assign the correct category for the underlined atom based on the product of complete hydrolysis at $R.T.$:
$\underline{S}O_2Cl_2 + H_2O \longrightarrow H_2SO_4 + HCl$

Calculate the consecutive oxidation numbers of $Br$ in $Br_3O_8$.