$6 \times 10^{-3}$ mole $K_2Cr_2O_7$ reacts completely with $9 \times 10^{-3}$ mole $X^{n+}$ to give $XO_3^-$ and $Cr^{3+}$. The value of $n$ is

$2 IO_3^- + x I^- + 12 H^+ \rightarrow 6 I_2 + 6 H_2 O$. What is the value of $x$?

Write the net ionic equation for the reaction of potassium dichromate$(VI)$,$K_{2}Cr_{2}O_{7}$ with sodium sulphite,$Na_{2}SO_{3}$ in an acidic solution to give chromium$(III)$ ion and the sulphate ion.

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.

$KMnO_4$ reacts in alkaline medium as follows:
$2KMnO_4 + 2KOH \to 2K_2MnO_4 + H_2O + O$
What is the equivalent weight of $KMnO_4$?
(Atomic weights: $K = 39, Mn = 55, O = 16$)

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$I_2 + S_2O_3^{2-} \longrightarrow I^{-} + S_4O_6^{2-}$