The number of electrons required to balance the following equation $NO_3^- + 4H^+ + x e^- \to 2H_2O + NO$ is

The equivalent weight of $MnSO_4$ is half of its molecular weight when it is converted to

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$4FeCr_2O_4 + 8Na_2CO_3 + 7O_2 \longrightarrow 2Fe_2O_3 + 8Na_2CrO_4 + 8CO_2$

Consider the following redox reaction taking place in acidic medium: $BH_{4}^{-}(aq) + ClO_{3}^{-}(aq) \rightarrow H_{2}BO_{3}^{-}(aq) + Cl^{-}(aq)$. If the Nernst equation for the above balanced reaction is $E_{cell} = E_{cell}^{o} - \frac{RT}{nF} \ln Q$, then the value of $n$ is . . . . . . . (Nearest integer)

The number of moles of $K_2Cr_2O_7$ reduced by $1 \, mol$ of $Sn^{2+}$ is:

$6 Fe_3O_4 + 2 MnO_4^- + H_2O \to 9 Fe_2O_3 + 2 MnO_2 + 2 OH^-$ Calculate the equivalent weight of $Fe_3O_4$ in the above equation.