The total change in the oxidation state of manganese involved in the reaction of $KMnO_4$ and potassium iodide in the acidic medium is $..........$.

Write the balanced chemical equation for the following reaction:
$Cl_2O_7$ in the gaseous state combines with an aqueous solution of hydrogen peroxide $(H_2O_2)$ in an acidic medium to give chlorite ion $(ClO_2^-)$ and oxygen gas $(O_2)$. (Balance by the ion-electron method)

For the balanced redox reaction $xMnO_4^- + yC_2O_4^{2-} + zH^+ \to Mn^{2+} + CO_2 + H_2O$,the values of $x, y$ and $z$ are respectively:

Only $2 \ mL$ of $KMnO_4$ solution of unknown molarity is required to reach the end point of a titration of $20 \ mL$ of oxalic acid $(2 \ M)$ in acidic medium. The molarity of $KMnO_4$ solution should be . . . . . . . . . $M$.

The product of $I^-$ with $MnO_4^-$ in alkaline medium is

When $4$ moles of electrons are added to $NO_3^-$,the product obtained is .......