I am not a professional chemist, but I believe the reason some people aren't getting the reaction creating FeCl<sub>2 is because these days, steel wool has a lot of other things in it other than iron and carbon. other compounds are added to make it more flexible, durable, and rust-proof.
I put a 1x1x3" wad of medium-fineness steel wool in a jar and covered it with 31.45% HCl. For a day or so nothing happened, but when i checked back on it nine days later, the steel wool had completely dissolved. There were a lot of incredibly fine black particles on the bottom, and when the jar was shaken, they stayed suspended for 2 days. I did put a metal screw-on lid on the jar, and after 9 days it was bent outward quite a bit due to the pressure of the hydrogen that was released from the HCl when the chlorine bonded with the iron.
aside from the black particles, which i believe to be carbon and other impurities, the solution was completely clear, no green, brown or yellow. Any reasons/thoughts?
The Golden Book of Chemistry describes this reaction a bit in its instructions on creating ferrous, and then ferric salt on page 68. The Golden Book can be downloaded legally and for free from this website:
http://chemistry.about.com/b/2008/08/05/banned-book-the-golden-book-of-chemistry-experiments.htm
