Which of the following is not a redox reaction?

Assign $A, B, C, D$ from the given type of reaction.
$Ba(OH)_2 + CO_2 \longrightarrow BaCO_3 \downarrow + H_2O$

How many electrons $(e^-)$ are gained by the oxidizing agent $KMnO_4$ to convert into $MnO_4^{2-}$,$MnO_2$,$Mn_2O_3$,and $Mn^{2+}$ respectively?

Which of the following reactions is $NOT$ an intermolecular redox reaction?

Match List-$I$ with the List-$II$.

List-$I$ (Reaction)	List-$II$ (Type of redox reaction)
$A$. $N_{2(g)} + O_{2(g)} \rightarrow 2 NO_{(g)}$	$I$. Decomposition
$B$. $2 Pb(NO_3)_{2(s)} \rightarrow 2 PbO_{(s)} + 4 NO_{2(g)} + O_{2(g)}$	$II$. Displacement
$C$. $2 Na_{(s)} + 2 H_2 O_{(l)} \rightarrow 2 NaOH_{(aq)} + H_{2(g)}$	$III$. Disproportionation
$D$. $2 NO_{2(g)} + 2 OH^-_{(aq)} \rightarrow NO^-_{2(aq)} + NO^-_{3(aq)} + H_2 O_{(l)}$	$IV$. Combination

Choose the correct answer from the options given below:

$A$ given amount of $Fe^{2+}$ is oxidized by $x \ mol$ of $MnO_{4}^{-}$ in acidic medium. The number of moles of $Cr_{2}O_{7}^{2-}$ required to oxidize the same amount of $Fe^{2+}$ in acidic medium is