Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
-----------------
manganese (II) sulfate : MnSO4 . H2O
sodium metaperiodate : NaIO4
Class:
------
elem=Mn,I
coordination
redox
Summary:
--------
Manganese (II) ions and periodate react with each other, even at room
temperature to form a peculiar brown precipitate with a pink/orange hue.
Certainly not the common dark brown manganese (IV) oxide/hydroxide is formed,
but a much lighter colored precipitate.
Description:
------------
Add a solution of manganese sulfate to an excess amount of a solution of sodium
metaperiodate: Immediately, a nice brown precipitate with a pink/orange hue is
formed. The color of this precipitate is remarkably bright. It is a little bit
like rust or iron (III) hydroxide, but a little bit more towards pink.
Allow the precipitate to settle: The liquid above the precipitate is bright
pink/purple and clear. This is the color of permanganate.
Carefully boil the liquid with the precipitate: The precipitate becomes more
coarse and curdy. It quickly settles at the bottom, when allowed to stand. The
color of the precipitate does not change noteworthy, the liquid itself becomes
slightly deeper purple/pink.
Most likely, the precipitate is a manganese (III) or manganese (IV) compound,
with a form of periodate in the precipitate as well.