The oxidation number of $S$ in $Na_2S_4O_6$ is ...........

What is the change in oxidation number of carbon in the following reaction?
$CH_{4(g)} + 4Cl_{2(g)} \rightarrow CCl_{4(l)} + 4HCl_{(g)}$

Find the oxidation number of $Cl$ in $ClO_4^-$

What are the oxidation numbers of nitrogen in $NH_4NO_3$?

$1 \ mol$ of compound $N_2H_4$ loses $10 \ mol$ of electrons to form a new compound $Y$. Assuming all nitrogen atoms are present in compound $Y$,what is the oxidation state of $N$ in compound $Y$?

$A$ compound contains atoms $X$,$Y$,and $Z$. The oxidation number of $X$ is $+2$,$Y$ is $+5$ and $Z$ is $-2$. Therefore,a possible formula of the compound is