After balancing the reaction $Cu + HNO_3 \rightarrow Cu(NO_3)_2 + NO_2 + H_2O$ in an acidic medium,the number of nitrogen atoms,the number of water molecules,and the net charge on the product side are respectively:

Assuming complete ionisation,same moles of which of the following compounds will require the least amount of acidified $KMnO_4$ for complete oxidation?

$MnO_4^{-}$ reacts with $A^{x+}$ to form $AO_3^{-}$,$Mn^{2+}$ and $O_2$. One mole of $MnO_4^{-}$ oxidizes $1.25$ moles of $A^{x+}$ to $AO_3^{-}$. What is the value of $x$?

In an alkaline medium,$ClO_2$ oxidizes $H_2O_2$ to $O_2$ and is reduced to $Cl^-$. How many moles of $H_2O_2$ will be oxidized by $1$ mole of $ClO_2$?

Assign $A, B, C, D$ from the given type of reaction.
$Mg_{(s)} + 2H_2O_{(l)} \xrightarrow{\text{Warm}} Mg(OH)_{2(aq)} + H_{2(g)} \uparrow$

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)