In ferrous ammonium sulphate,the oxidation number of $Fe$ is:

What is the correct order of decreasing oxidation state of iodine in the following compounds?

What is the oxidation state of $S$ in $H_2SO_3$?

$A$ compound contains atoms of $x, y$ and $z$ elements. Oxidation numbers of $x, y$ and $z$ are $+3, +5$ and $-2$ respectively. Identify the possible formula of this compound?

The oxidation states of $S$ in peroxodisulphuric acid $(H_{2}S_{2}O_{8})$ and sodium tetrathionate $(Na_{2}S_{4}O_{6})$ are respectively:

$1 \ mol$ 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 $Y$?