Generally transition elements form coloured salts due to the presence of unpaired electrons. Which of the following compounds will be coloured in the solid state?

Which of the following reactions are disproportionation reactions?

${\mathrm{Cu}}^{+}⟶{\mathrm{Cu}}^{2+}+\mathrm{Cu}$

$3{\mathrm{MnO}}_4^{2-}+4{\mathrm{H}}^{+}⟶2{\mathrm{MnO}}_4^{-}+{\mathrm{MnO}}_2+2{\mathrm{H}}_2\mathrm{O}$

$2{\mathrm{KMnO}}_4⟶{\mathrm{K}}_2{\mathrm{MnO}}_4+{\mathrm{MnO}}_2+{\mathrm{O}}_2$

$2{\mathrm{MnO}}_4^{-}+3{\mathrm{Mn}}^{2+}+2{\mathrm{H}}_2\mathrm{O}⟶5{\mathrm{MnO}}_2+4{\mathrm{H}}^{+}$

 Which of the following are amphoteric oxides: 

${\mathrm{Mn}}_2{\mathrm{O}}_7, {\mathrm{CrO}}_3, {\mathrm{Cr}}_2{\mathrm{O}}_3, \mathrm{CrO}, {\mathrm{V}}_2{\mathrm{O}}_5,{ \mathrm{V}}_2{\mathrm{O}}_4$