The heating of $(NH_4)_2Cr_2O_7$ produces another chromium compound along with $N_2$ gas. The change of the oxidation state of $Cr$ in the reaction is

In the ionic equation $BiO_{3}^{-} + 6H^{+} + x e^{-} \longrightarrow Bi^{3+} + 3H_{2}O$,the value of $x$ is:

The number of moles of acidified $KMnO_4$ required to convert one mole of sulphite ion into sulphate ion is

For the reaction $I^{-} + ClO_3^{-} + H_2SO_4 \to Cl^{-} + HSO_4^{-} + I_2$ (no free $H^{+}$ is present),select the correct statement for the balanced equation (coefficients in smallest whole number ratio).

Assign $A, B, C, D$ from the given types of reactions:
$A$: Disproportionation reaction.
$B$: Comproportionation reaction.
$C$: Either intermolecular redox reaction or displacement reaction.
$D$: Either thermal combination redox reaction or thermal decomposition redox reaction.
Reaction: $MnO_4^- + H^+ + Br^- \longrightarrow Mn^{2+}(aq.) + Br_2 \uparrow$

In the reaction $I_2 + 2S_2O_3^{2-} \to 2I^{-} + S_4O_6^{2-}$,the equivalent weight of iodine will be equal to