In an acidic medium,the dichromate ion oxidizes the ferrous ion to the ferric ion. If the molar mass of potassium dichromate is $294 \, g/mol$,what is its equivalent mass?

Manganese ions $(Mn^{2+})$ can be oxidised by persulphate ions $(S_2O_8^{2-})$ according to the following half-equations:
$S_2O_8^{2-} + 2e^- \longrightarrow 2SO_4^{2-}$
$Mn^{2+} + 4H_2O \longrightarrow MnO_4^- + 8H^+ + 5e^-$
How many moles of $S_2O_8^{2-}$ are required to oxidise $1 \ mole$ of $Mn^{2+}$?

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:

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$PbO_2 + 4HNO_3 (Conc.) \longrightarrow Pb(NO_3)_2 + 2H_2O + O_2$

$Mg$ (Magnesium) burns in $CO$ to produce

When neutral or faintly alkaline $KMnO_4$ is treated with potassium iodide,iodide ion is converted into '$X$'. '$X$' is