Which of the following reduction products of $NO_3^-$ involves the maximum number of moles of electrons taken up per mole of $NO_3^-$?

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$3AgNO_3 + Na_3PO_4 \longrightarrow Ag_3PO_4 \downarrow + 3NaNO_3$

In acidic medium,the required number of moles of ferrous oxalate $(FeC_2O_4)$ for the reduction of $2.5 \, mol$ of $KMnO_4$ is:

Assign $A, B, C, D$ from the given type of reaction: $2NaNO_3 + H_2SO_4(conc.) \xrightarrow{Hot} Na_2SO_4 + 2NO_2 + \frac{1}{2}O_2 + H_2O$. (Note: The reaction is a thermal decomposition redox reaction).

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

List-$I$ (Types of redox reactions)	List-$II$ (Examples)
$a.$ Combination reaction	$(i)$ $Cl_{2(g)} + 2Br^-_{(aq)} \rightarrow 2Cl^-_{(aq)} + Br_{2(l)}$
$b.$ Decomposition reaction	$(ii)$ $2H_2O_{2(aq)} \rightarrow 2H_2O_{(l)} + O_{2(g)}$
$c.$ Displacement reaction	$(iii)$ $CH_{4(g)} + 2O_{2(g)} \xrightarrow{\Delta} CO_{2(g)} + 2H_2O_{(l)}$
$d.$ Disproportionation reaction	$(iv)$ $2H_2O_{(l)} \xrightarrow{\text{electrolysis}} 2H_{2(g)} + O_{2(g)}$

Choose the correct answer from the options given below.

Acidified potassium permanganate solution is decolourised by