I reduced a bunch of fairly weak material with Zn and HCl, and following basification and freeze precipitation I placed a bunch of wet freebase on aluminium foil for solvent evaporation. When I came back maybe 30-40mins later I noticed both the spice and foil gone dark gray to black at the point of contact.
What sort of chemical reaction is this and how would you get rid of it?
What sort of chemical reaction is this and how would you get rid of it?
