chemkid - 21-10-2007 at 09:48
I reacted aluminium foil with muriatic acid until no more aluminium would react. The reaction formed a gray foam of bubbles. I left the beaker out
overnight with a watch glass over it to allow any remaining aluminium flakes to react. In the morning i found there was still a gray precipitant. It
measured a very low pH (cabbage indicator solution and pH paper). The precipitant did not dissolve with water or HCl. The precipitant seemed to float
on the solution but i am not sure of that. Filtration yielded a gray filtrate.
To the best of my knowledge aluminium chloride is yellow and soluble in water. I don't think it was aluminium because that would have reacted upon the
addition of more acid. Perhaps an impurity in the metal. Any insight on what the precipitant may be and if this is normal would be appreciated.
Furthermore , why does the reaction of aluminium and HCl turn gray?
Chemkid
12AX7 - 21-10-2007 at 10:53
Could be silicon and other impurities.
Tim
Polverone - 21-10-2007 at 11:20
If you still think this is a mystery, consider continuing discussion in the mystery reaction thread.