Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
-----------------
ammonia : NH3
hydroxyl amine sulfate : (NH3OH)2 SO4
sodium thiocyanate : NaSCN
silver nitrate : AgNO3
Class:
------
elem=Ag
precipitation
Summary:
--------
Silver (I) gives a white precipitate with thiocyanate, which does not dissolve
in excess ammonia. Hydroxyl amine does not affect this precipitate.
Description:
------------
Add a solution of silver nitrate (appr. 25 g/l) to a solution of sodium
thiocyanate (appr. 2 mol/l): Formation of a white precipitate with a fairly
coarse structure. The precipitate goes to the bottom quickly.
Add a large excess amount of NH3 (appr. 5% by weight): The precipitate becomes
light brown, it does not dissolve.
Add some solid hydroxyl amine sulfate: The hydroxyl amine sulfate dissolves,
the brown prcipitate does not change visibly.
Heat to appr. 60C: No visible change, except that the precipitate appears to
obtain a slightly coarser structure.