Select the correct statements with respect to the manganese nitrate solution in water :

MKanganese nitrate solution in water  gives pink precipitate of $\mathrm{Mn}\left({\mathrm{NH}}_4\right){\mathrm{PO}}_4\cdot 7{\mathrm{H}}_2\mathrm{O}$ with ${\mathrm{Na}}_2{\mathrm{HPO}}_4$ in the presence of ammonia solution.

It gives white precipitate of $\mathrm{Mn}(\mathrm{OH}{)}_2$ with sodium hydroxide which rapidly oxidises on exposure to air, becoming brown.

${\mathrm{HMnO}}_4$ (Violet colour) is formed.

$\text{ MnS↓}$ (Buff colour ppt.)

On boiling with ${\mathrm{PbO}}_2$ and concentrated ${\mathrm{HNO}}_3$, a violet-red coloured product is obtained.