In my chem class we have to identify different chemicals. They are all in droppers and one of the droppers has a brown residue around the inside that sometimes comes out with the solution. Sometimes it doesn't and then the solution is colorless. Is it Ammonium Chloride, Sulfuric Acid, Nitric acid, Barium Nitrate,silver Nitrate, or Potassium Nitrate?
-
When silver nitrate is exposed to light it precipitates out silver - that may be your brown residue.
-
That would be silver nitrate.