$KMnO_4$ 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 $/5$)?

Chlorine undergoes disproportionation in alkaline medium as shown below:
$a Cl_{2(g)} + b OH^{-}_{(aq)} \rightarrow c ClO^{-}_{(aq)} + d Cl^{-}_{(aq)} + e H_2O_{(l)}$
The values of $a, b, c$ and $d$ in a balanced redox reaction are respectively:

The reaction of sulphur in alkaline medium is given below:
$S_{8(s)} + a OH^{-}_{(aq)} \rightarrow b S^{2-}_{(aq)} + c S_{2}{O_{3}}^{2-}_{(aq)} + d H_{2}O_{(\ell)}$
The value of '$a$' is ............ (Integer answer)

If the molecular weights of $Na_2S_2O_3$ and $I_2$ are $M_1$ and $M_2$ respectively, then what will be the equivalent weights of $Na_2S_2O_3$ and $I_2$ in the following reaction?
$2S_2O_3^{2-} + I_2 \longrightarrow S_4O_6^{2-} + 2I^-$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$I_2 + S_2O_3^{2-} \longrightarrow I^{-} + S_4O_6^{2-}$

In acidic medium,potassium dichromate acts as an oxidant according to the equation,$Cr_2O_7^{2-} + 14H^{+} + 6e^- \to 2Cr^{3+} + 7H_2O$. What is the equivalent weight of $K_2Cr_2O_7$? (Molecular weight $= M$)