In mildly alkaline medium,thiosulphate ion is oxidized by $MnO_4^-$ to $A$. The oxidation state of sulphur in $A$ is ..... .

How many moles of electrons are needed to convert one mole of nitrate ion to hydrazine?

How many moles of acidified $K_{2}Cr_{2}O_{7}$ are required to liberate $6$ moles of $I_{2}$ from an aqueous solution of $I^{-}$?

In neutral or faintly alkaline medium,$KMnO_4$ being a powerful oxidant can oxidize thiosulphate almost quantitatively to sulphate. In this reaction,the overall change in the oxidation state of manganese will be:

In acidic medium,dichromate ion oxidises ferrous ion to ferric ion. If the gram molecular weight of potassium dichromate is $294 \ g$,its gram equivalent weight is $...$ grams.

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 . . . . . . . . . $M$.