In which of the following reactions does $HNO_3$ $NOT$ act as an oxidizing agent?

To an acidified dichromate solution,a pinch of $Na_2O_2$ is added and shaken. What is observed?

$2 \text{ mol}$ of $FeSO_4$ are oxidized by $X \text{ mol}$ of $KMnO_4$ whereas $2 \text{ mol}$ of $FeC_2O_4$ are oxidized by $Y \text{ mol}$ of $KMnO_4$. The ratio of $X$ and $Y$ is:

The following reaction describes the rusting of iron:
$4Fe + 3O_2 \to 4Fe^{3+} + 6O^{2-}$
Which one of the following statements is incorrect?

Which is not the true statement about $KMnO_4$?

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.