The equivalent weight of $Na_2S_2O_3$ (Gram molecular weight $= M$) in the given reaction is $I_2 + 2Na_2S_2O_3 \rightarrow 2NaI + Na_2S_4O_6$.

Which of the following is a redox reaction?

True or False: In the reaction $Cr_2O_7^{2-} \xrightarrow{H^{+}} Cr^{3+}$,the equivalent mass of $Cr_2O_7^{2-}$ is $\frac{\text{molecular mass}}{6}$.

$KMnO_4$ oxidises hydrogen sulphide in acidic medium. The number of moles of $KMnO_4$ which react with one mole of hydrogen sulphide is

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

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.