In the reaction $3I_2 + 6NaOH \to NaIO_3 + 5NaI + 3H_2O$,which substance acts as the oxidizing agent?

Which of the following substances acts as an oxidising as well as a reducing agent?

In the following reaction,assign the state for the underlined atom in the products of complete hydrolysis at $R.T.$: $\underline{N}_2O_4 + H_2O \longrightarrow HNO_3 + HNO_2$

Which anion can undergo both oxidation and reduction?

Total number of species from the following which can undergo disproportionation reaction . . . . . . .
$H_2O_2$,$ClO_3^{-}$,$P_4$,$Cl_2$,$Ag$,$Cu^{+}$,$F_2$,$NO_2$,$K^{+}$

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$P_4 + 3NaOH + 3H_2O \longrightarrow PH_3 + 3NaH_2PO_2$
(Note: The reaction provided is the standard balanced equation for the disproportionation of white phosphorus.)