$10 \, \text{mole}$ of ferric oxalate is oxidised by $x \, \text{mole}$ of $MnO_4^-$ in acidic medium. The value of $x$ is

If stoichiometric quantities of a $KMnO_4$ and $K_2Cr_2O_7$ mixture are added for the oxidation of $Fe^{2+}$ to $Fe^{3+}$ in an acidic medium,then $Fe^{2+}$ will be oxidized:

$I^{-}(aq.) + MnO_4^{-}(aq.) \xrightarrow{H^{+}} X + Mn^{2+}(aq.)$
$I^{-}(aq.) + MnO_4^{-}(aq.) \xrightarrow{\text{Neutral or weakly } OH^{-}} Y + MnO_2$
$MnO_4^{-}(aq.) + Mn^{2+}(aq.) \xrightarrow{ZnSO_4} Z + 4H^{+}$
Products $X, Y$ and $Z$ are respectively :

$A$ solution of $KMnO_4$ on reduction yields either a colourless solution,a brown precipitate,or a green solution depending on the $pH$ of the solution. What different stages of the reduction do these represent and how are they carried out?

When $SO_2$ is bubbled into an acidic $KMnO_4$ solution,decolorization of the purple solution takes place along with the formation of a manganese compound $X$. Under neutral conditions,compound $X$ reacts with $KMnO_4$ in the presence of zinc oxide to give another manganese compound $Y$. The oxidation states of manganese in compounds $X$ and $Y$,respectively,are

Which of the following is not a redox reaction?