In dilute alkaline solution,$MnO_4^-$ changes to:

$MnO_4^{-}$ oxidises $(i)$ oxalate ion in acidic medium at $333 \ K$ and $(ii)$ $HCl$. For balanced chemical equations,the ratios $[MnO_4^{-} : C_2O_4^{2-}]$ in $(i)$ and $[MnO_4^{-} : HCl]$ in $(ii)$ respectively are

The equivalent weight of $MnSO_4$ is half of its molecular weight when it is converted to

$KMnO_4$ in basic medium is reduced to

Justify that the reaction:
$2 Cu_{2}O_{(s)} + Cu_{2}S_{(s)} \rightarrow 6 Cu_{(s)} + SO_{2(g)}$
is a redox reaction. Identify the species oxidised/reduced,which acts as an oxidant and which acts as a reductant.

In a weak alkaline medium,iodide is changed into which of the following compounds by $KMnO_4$?