The dibasic oxoacid of phosphorus on disproportionation gives two products $A$ and $B$. $A$ and $B$ are respectively

Which of the following does not undergo a comproportionation reaction?

Statement-$1$ : $I_2 \rightarrow IO_3^- + I^-$; This is a disproportionation reaction.
Statement-$2$ : Oxidation number of $I$ can vary from $-1$ to $+7$.

$PhCHO \xrightarrow{OH^{-}} PhCH_2OH + PhCOO^{-}$
This reaction is an example of -

Among $P_4$,$S_8$ and $N_2$,the elements which undergo disproportionation when heated with $NaOH$ solution are:

The disproportionation of $MnO_{4}^{2-}$ in acidic medium results in the formation of two manganese compounds $A$ and $B$. If the oxidation state of $Mn$ in $B$ is smaller than that of $A$,then the spin-only magnetic moment $(\mu)$ value of $B$ in $BM$ is $.........$ (Nearest integer).