In the reaction $A^{-n_2} + x e^- \to A^{-n_1}$,the value of $x$ is:

What is the charge required to convert $2 \ mol$ of $KMnO_4$ to $MnSO_4$ (in $F$)?

In the following balanced chemical reaction,$IO_3^- + aI^- + bH^+ \to cH_2O + dI_2$,what are the values of $a, b, c$ and $d$ respectively?

How many grams of $Mg$ is required to completely reduce $100 \ mL$ of $0.1 \ M$ $NO_3^{-}$ solution using the following reaction:
$NO_3^{-} + Mg \longrightarrow Mg^{2+} + NH_3$

In acidic medium,the equivalent weight of $K_2Cr_2O_7$ $(mol. wt. = M)$ is

Assign $A, B, C, D$ from the given type of reaction for the following chemical equation:
$Fe_{(s)} + 2HCl_{(aq)} \longrightarrow FeCl_{2(aq)} + H_{2(g)}$