Nitrous acid was disproportionated to form water,$HNO_3$ and $X$. In another reaction,sodium nitrite was reacted with $H_2SO_4$ to form $NaHSO_4, HNO_3$,water and $Y$. What are $X$ and $Y$ respectively?

Auto-oxidation of bleaching powder gives

Which of the following does not show a disproportionation reaction?

What is obtained when $H_2S$ gas is passed through $Hg_2^{2+}$ solution?

Which species among the following does not show disproportionation reactions?

From the given reactions, identify the disproportionation reaction:
$(i) \ Cl_{2(g)} + 2KI_{(aq)} \longrightarrow 2KCl_{(aq)} + I_{2(s)}$
$(ii) \ Cl_{2(g)} + 2OH^{-}_{(aq)} \longrightarrow ClO^{-}_{(aq)} + Cl^{-}_{(aq)} + H_2O_{(l)}$
$(iii) \ Mg_{(s)} + 2HCl_{(aq)} \longrightarrow MgCl_{2(aq)} + H_{2(g)}$
$(iv) \ 2H_2O_{2(aq)} \longrightarrow 2H_2O_{(l)} + O_{2(g)}$