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

In the reaction,$4Fe + 3O_2 \to 4Fe^{3+} + 6O^{2-}$,which of the following statements is incorrect?

Assign $A, B, C, D$ for the given type of reaction: $CuSO_4$ (solution) + $ZnCl_2$ (solution) $\longrightarrow$ No reaction.

Identify whether the following reactions act as oxidation or reduction processes:
$(i) \ S + 6HNO_3 \to H_2SO_4 + 6NO_2 + 2H_2O$
$(ii) \ 2K + Br_2 \to 2KBr$

Assign $A, B, C, D$ from the given type of reaction.
$PbCrO_4 \downarrow + 4NaOH \,(Excess) \longrightarrow Na_2[Pb(OH)_4] + Na_2CrO_4$

Identify the substance acting as an oxidant in the following reaction:
$BaCl_2 + Na_2SO_4 \to BaSO_4 + 2NaCl$