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

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

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	$(iv)$ $KClO_3 \xrightarrow{\Delta} KCl + O_2$

Which of the following reactants can be reduced by $SO_2$ in the given reactions?
$(I)$ $O_3 \to$ product
$(II)$ $Cr_2O_7^{2-} \xrightarrow{H^{+}} $ product
$(III)$ $MnO_4^{-} \xrightarrow{H^{+}} $ product
$(IV)$ $H_2S \to$ product

Assign $A, B, C, D$ from the given type of reaction.
$CrCl_3$ $(aq)$ + $ZnSO_4$ $(aq)$ $\longrightarrow$ No reaction

Which gases are formed by the oxidation of carbon with concentrated $H_2SO_4$?