kvark - 18-2-2008 at 13:24
Hi this is my first post !
Today i have experimenting with FeSO4. I made a FeSO4 (aq)+KOH--->Fe(OH)2+K2SO4 and than i want to made Fe2O3 with heating Fe(OH)2. But I get some
gray dust what did i get ?
Sorry for my English I come from Slovenia.
12AX7 - 18-2-2008 at 22:43
Fe(OH)2 is gray. It should oxidize readily in air to an orange product, especially if heated in air.
Tim
Xenoid - 19-2-2008 at 14:12
As an adjunct to what 12AX7 has said, here is some information from my Mellor's;
"Ferrous hydroxide, Fe(OH)2 is obtained as a white precipitate when solutions of alkali hydroxides are added to a solution of a ferrous salt, with
COMPLETE EXCLUSION of air. If the solutions contain dissolved air, the precipitate has a greenish colour. It rapidly absorbs oxygen and passes into
brown ferric hydroxide, Fe(OH)3 .... On drying and heating this passes into ferric oxide, Fe2O3 .... The particular tint of ferric oxide depends upon
the temperature of calcination, which appears to determine the size of particles. When prepared at low temperatures, ferric oxide dissolves fairly
easily in acids, forming ferric salts, but if heated above 600 oC. acids only attack it with difficulty .... Fe2O3 is stable at red heat, but above
about 1300 oC. it decomposes into Fe3O4, (magnetite, black colour) ... "
[Edited on 19-2-2008 by Xenoid]