"the other day I was refluxing hexamine with a slight overdose of HCl forgetting about the stainless steel stir shaft in the flask, so after 4 hours
the solution was dark green and some of the shaft was gone.
Cooled and filtered out the yellow/green crystals but they didn't look like NH4Cl, they were more like tiny shards of broken glass and sand. So what
have I cooked? What are these crystals?"chemoleo - 18-3-2006 at 19:22
FeCl2 * 6H2O?
You just dissolved the steel presumably.woelen - 19-3-2006 at 11:31
Quote:
Originally posted by chemoleo
FeCl2 * 6H2O?
You just dissolved the steel presumably.
Iron (II) forms a tetrahydrate, so I would say
FeCl2.4H2O.
But in reality, I think it is a mix of iron (III) and chromium (III). Iron salt solutions are not dark green. Iron (II) is almost colorless or very
pale green at high concentration and it gives pale blue/green crystals.
Iron (III) in the presence of hydrochloric acid forms deep yellow solutions, due to formation of the complex FeCl4(-).
Chromium, when dissolved in hydrochloric acid, with air allowed to reach the mixture, forms a green solution of a chloro complex of chromium (III).
The yellow/green crystals probably are impure FeCl3.6H2O, contaminated with chromium (III), hence the green hue.
