What is the value of $n$-factor of $[Fe(CN)_6]^{-4}$ in the given reaction?
$[Fe(CN)_6]^{-4} \xrightarrow{MnO_4^-/H^{+}} Fe^{+3} + CO_2 + NO_3^-$

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.

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$S + HNO_3 \, (Dil.) \longrightarrow H_2SO_4 + NO \uparrow $

Oxidation of thiosulphate $S_2O_3^{2-}$ ion by iodine gives

In the ionic equation $BiO_{3}^{-} + 6H^{+} + x e^{-} \longrightarrow Bi^{3+} + 3H_{2}O$,the value of $x$ is:

$aIO_3^- + bI^- + 6H^+ \to cI_2 + 3H_2O$
In the above reaction,the coefficients $a$,$b$,and $c$ are respectively: