In the following reaction $P_4 + 3NaOH + 3H_2O \to PH_3 + 3NaH_2PO_2$,what happens to phosphorus?

Consider the following reaction,
$3Br_2 + 6CO_3^{2-} + 3H_2O \longrightarrow 5Br^{-} + BrO_3^- + 6HCO_3^-$
Which of the following statements is true regarding this reaction?

Which of the following species do not show disproportionation reaction and why?
$ClO^{-}, ClO_{2}^{-}, ClO_{3}^{-}$ and $ClO_{4}^{-}$
Also write the reaction for each of the species that disproportionates.

Which of the following is not a disproportionation reaction?

Given below are two statements :
Statement $I$: $S_8$ solid undergoes disproportionation reaction under alkaline conditions to form $S^{2-}$ and $S_2O_3^{2-}$.
Statement $II$: $ClO_4^{-}$ can undergo disproportionation reaction under acidic condition.
In the light of the above statements,choose the most appropriate answer from the options given below :

$1 \text{ mole}$ 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 $Mn = 55 \ g/mol$).