The number of moles of acidified $KMnO_4$ required to convert one mole of sulphite ion into sulphate ion is

Identify the correct statements about the following stoichiometric equation.
$aP_4 + bOH^{-} + cH_2O \longrightarrow dPH_3 + eH_2PO_2^{-}$
$I$. $a+b+c=5$
$II$. $b+c-e=3$
$III$. The oxidation state of $P$ in $H_2PO_2^{-}$ is $+1$.

For the balanced equation $NO_3^- + 4H^+ + ne^- \to 2H_2O + NO$,the value of $n$ is ........

$KMnO_4$ oxidises oxalic acid to $CO_2$ in acidic medium. The equivalent weight of $KMnO_4$ is $(Mn = 55, K = 39, O = 16)$:

Number of moles of $MnO_4^-$ required to oxidize one mole of ferrous oxalate completely in acidic medium will be .......... $moles$.

When neutral or faintly alkaline $KMnO_4$ is treated with potassium iodide,iodide ion is converted into '$X$'. '$X$' is