Which of the following is a disproportionation redox reaction?

$1 \text{ mole}$ of $MnO_4^{2-}$ disproportionates into $MnO_4^-$ and $MnO_2$ in an acidic medium. Calculate the percentage by mass of $Mn$ converted to $MnO_4^-$ (Molar mass of $Mn = 55 \ g/mol$).

Which of the following are disproportionation reactions?
$(A)$ $Cl_2 + 2 NaOH \rightarrow NaCl + NaOCl + H_2O$
$(B)$ $2 H_2O_2 \rightarrow 2 H_2O + O_2$
$(C)$ $2 KMnO_4 \rightarrow K_2MnO_4 + MnO_2 + O_2$
$(D)$ $3 MnO_4^{2-} + 4 H^+ \rightarrow 2 MnO_4^- + MnO_2 + 2 H_2O$

Assign $A, B, C, D$ from the given type of reaction.
$Na_2S + H_2SO_4$ $(Conc.)$ $\longrightarrow S\downarrow + SO_2 + Na_2SO_4$

Assign $A, B, C, D$ from the given type of reaction.
$N_2O_3 \xrightarrow{R.T.} NO + NO_2$

Assign $A, B, C, D$ from the given type of reaction.
$K_2MnO_4 + H^{+} \longrightarrow KMnO_4 + MnO_2 \downarrow$