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

Match the following types of reactions in List-$I$ with their corresponding unbalanced equations in List-$II$.

List-$I$ (Type of reaction)	List-$II$ (Unbalanced equation)
$A$. Combination reaction	$(i)$ $AgNO_3 + CaCl_2 \longrightarrow AgCl + Ca(NO_3)_2$
$B$. Decomposition reaction	$(ii)$ $Cl_2 \longrightarrow Cl^- + ClO_3^-$
$C$. Disproportionation reaction	$(iii)$ $Mg + N_2 \longrightarrow Mg_3N_2$
$D$. Displacement reaction	$(iv)$ $KClO_3 \xrightarrow{\Delta} KCl + O_2$

$20 \ mL$ of $Fe^{2+}$ solution of certain concentration has completely reacted with $20 \ mL$ of $0.01 \ M \ K_2Cr_2O_7$ in acidic medium. If $20 \ mL$ of same $Fe^{2+}$ solution has reacted completely with $20 \ mL$ of $KMnO_4$ solution in acidic medium,the molarity of $KMnO_4$ solution is: (in $M$)

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?

$PbO$ and $PbO_2$ react with $HCl$ according to the following chemical equations:
$(i)$ $2PbO + 4HCl \to 2PbCl_2 + 2H_2O$
$(ii)$ $PbO_2 + 4HCl \to PbCl_2 + Cl_2 + 2H_2O$
Why do these compounds differ in their reactivity?

What are $X$ and $Y$ in the following reactions?
$(i) \ MnO_4^{-} + I^{-} \xrightarrow{H^{+}} X$
$(ii) \ MnO_4^{-} + I^{-} \xrightarrow{H_2O} Y$