The product of oxidation of $I^{-}$ with $MnO_4^{-}$ in alkaline medium is

In the reaction of sodium thiosulphate with $I_2$ in aqueous medium, the equivalent weight of sodium thiosulphate is equal to:

$PbS + 4O_3 \,\to ?\,+\,4O_2$

$KMnO_4$ acts as an oxidising agent in acidic medium. The number of moles of $KMnO_4$ that will be needed to react with one mole of sulphide ion $(S^{2-})$ in acidic solution is . . . . . . (in $/5$)?

Assign $A, B, C, D$ from the given type of reaction.
$NaNO_2 + FeSO_4 + H_2SO_4 \longrightarrow [Fe(H_2O)_5NO]SO_4 + Na_2SO_4 + Fe_2(SO_4)_3 + H_2O$
Identify the type of reaction for the formation of the brown ring complex.

$KMnO_4$ reacts with $H_2O_2$ in an acidic medium. The number of moles of oxygen produced per mole of $KMnO_4$ is