Potassium permanganate works as an oxidising agent both in acidic and basic medium. In both states,the products obtained by $KMnO_4$ are respectively:

For the reaction $SO_2 + 2H_2S \to 3S + 2H_2O$,which option represents twice the equivalent weight of the oxidizing agent?

When an acidic solution of $K_2Cr_2O_7$ is added to $Na_2SO_3$,it turns green. Which of the following compounds is formed in this reaction?

In the reaction,$4Fe + 3O_2 \to 4Fe^{3+} + 6O^{2-}$,which of the following statements is incorrect?

Consider the following redox reaction in basic medium.
$x \ Cr(OH)_3 + y(IO_3)^{-} + z(OH)^{-} \rightarrow a(CrO_4)^{2-} + b(I)^{-} + c(H_2O)$
The incorrect option about it is

How do you account for the following observations?
$(a)$ Though alkaline potassium permanganate and acidic potassium permanganate both are used as oxidants,yet in the manufacture of benzoic acid from toluene,we use alcoholic potassium permanganate as an oxidant. Why? Write a balanced redox equation for the reaction.
$(b)$ When concentrated sulphuric acid is added to an inorganic mixture containing chloride,we get a colourless pungent-smelling gas $HCl$,but if the mixture contains bromide,then we get red vapour of bromine. Why?