In which reaction is there a change in the oxidation state?

$1$ mole of $PbS$ is oxidised by "$X$" moles of $O_3$ to get "$Y$" moles of $O_2$. $X + Y = $ . . . . . . .

Assign $A, B, C, D$ from the given types of reactions:
$A$: Disproportionation reaction.
$B$: Comproportionation reaction.
$C$: Either intermolecular redox reaction or displacement reaction.
$D$: Either thermal combination redox reaction or thermal decomposition redox reaction.
Reaction: $MnO_4^- + H^+ + Br^- \longrightarrow Mn^{2+}(aq.) + Br_2 \uparrow$

What is the number of moles of electrons gained by one mole of oxidizing agent in the following redox reaction?
$Zn_{(s)} + 2HCl_{(aq)} \longrightarrow ZnCl_2(aq) + H_2(g)$

What is the ratio of the stoichiometric coefficient of $N_2H_4$ to $Cl^-$ in the following balanced redox reaction?
$ClO_3^- + N_2H_4 \to NO_3^- + Cl^-$

In the reaction $M^{+x} + MnO_4^- \to MO_3^- + Mn^{+2}$,if $1 \ mol$ of $MnO_4^-$ oxidizes $1.67 \ mol$ of $M^{+x}$ to $MO_3^-$,find the value of $x$.