$Cu^{2+}(aq.)$ does not undergo a redox reaction with a solution of:

Match each of the reactions given in Column $I$ with the corresponding product$(s)$ given in Column $II$.

Column $I$	Column $II$
$(A)$ $Cu + \text{dil } HNO_3$	$(p)$ $NO$
$(B)$ $Cu + \text{conc } HNO_3$	$(q)$ $NO_2$
$(C)$ $Zn + \text{dil } HNO_3$	$(r)$ $N_2O$
$(D)$ $Zn + \text{conc } HNO_3$	$(s)$ $Cu(NO_3)_2$
	$(t)$ $Zn(NO_3)_2$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$KI + AgNO_3 \longrightarrow AgI + KNO_3$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Na_2CO_3 + Pb(NO_3)_2 \longrightarrow PbCO_3 \downarrow + 2NaNO_3$

Consider the following redox reaction in basic medium.
$x \ Cr(OH)_3 + y(IO_3)^{-} + z(OH)^{-} \rightarrow a(CrO_4)^{2-} + b(I)^{-} + c(H_2O)$
The incorrect option about it is

Which of the following species is both basic and a reducing agent?