$KMnO_4$ oxidises $I^{-}$ in acidic and neutral/faintly alkaline solution,respectively to

In which of the following conversions does a blue colour appear?

For the reaction: $4Fe + 3O_2 \rightleftharpoons 4Fe^{3+} + 6O^{2-}$,which of the following statements is $NOT$ correct?

Which of the following reactions represents a redox reaction involving water?

Observe the following reactions:
$(i)$ $2 KClO_{3(s)} \xrightarrow{\Delta} 2 KCl_{(s)} + 3 O_{2(g)}$
$(ii)$ $2 H_2O_{2(aq)} \xrightarrow{\Delta} 2 H_2O_{(l)} + O_{2(g)}$
$(iii)$ $AgNO_{3(aq)} + KCl_{(aq)} \longrightarrow AgCl_{(s)} + KNO_{3(aq)}$
$(iv)$ $2 Na_{(s)} + \frac{1}{2} O_{2(g)} \longrightarrow Na_2O_{(s)}$
The number of redox reactions in this list is

Which of the following reactions is a decomposition redox reaction?