In the reaction $I_2 + 2S_2O_3^{2-} \to 2I^{-} + S_4O_6^{2-}$,the equivalent weight of iodine will be equal to

Which of the following are redox changes?
$(i)$ Hydrolysis of $XeF_2$
$(ii)$ Thermal decomposition of $Ag_2CO_3$
$(iii)$ Reaction of $Al$ with $NaOH$
$(iv)$ Hydrolysis of $PCl_5$
$(v)$ Reaction of $NaCl$ with conc. $H_2SO_4$
Correct options are:

How many moles of $H_2SO_3$ are required to reduce one mole of $KMnO_4$ in an acidic medium?

Acidified potassium permanganate solution is decolourised by

In order to oxidize a mixture of one mole of each of $FeC_2O_4$,$Fe_2(C_2O_4)_3$,$FeSO_4$ and $Fe_2(SO_4)_3$ in acidic medium,the number of moles of $KMnO_4$ required is

Assign $A, B, C, D$ from the given type of reaction.
$Na_2[Zn(OH)_4] + 4HCl \longrightarrow ZnCl_2 + 2NaCl + 4H_2O$