Which of the following processes does not involve oxidation of iron?

Acidified potassium permanganate solution is decolourised by

$A$ sample $(5.6 \ g)$ containing iron is completely dissolved in cold dilute $HCl$ to prepare $250 \ mL$ of solution. Titration of $25.0 \ mL$ of this solution requires $12.5 \ mL$ of $0.03 \ M \ KMnO_4$ solution to reach the end point. The number of moles of $Fe^{2+}$ present in the $250 \ mL$ solution is $x \times 10^{-2}$ (consider complete dissolution of $FeCl_2$). The amount of iron present in the sample is $y \%$ by weight. (Assume: $KMnO_4$ reacts only with $Fe^{2+}$ in the solution. Use: Molar mass of iron as $56 \ g \ mol^{-1}$)
$(1)$ The value of $x$ is. . . . .
$(2)$ The value of $y$ is. . . . .

Assign $A, B, C, D$ from the given type of reaction.
$NO + NO_2 \xrightarrow{-11 \ ^{\circ}C} N_2O_3$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$Pb(CH_3COO)_2 + Na_2CrO_4 \longrightarrow PbCrO_4 \downarrow + 2CH_3COONa$

$2 Cu_2O_{(s)} + Cu_2S_{(s)} \longrightarrow 6 Cu_{(s)} + SO_{2(g)}$
In the above reaction,the oxidant and reductant respectively are: