Does a reaction occur when aqueous solutions of iron(II) chloride and potassium hydroxide are combined? If a reaction does occur, write the net ionic equation.

Answer 1

Hi Andres M.,

yes, the Fe²⁺ and Fe³⁺ cations only are stable in acidic aqueous media. In neutral or basic conditions they precipitate as neutral (OH)^- co-ordinated species. The iron cations are acidic enough that they pull in the O of water and persuade it to kick off an H cation. For the former, I believe the precipitate is termed Fe(OH)₂ , at least until it's calcined a bit. Then it turns to FeO. You can look up the TGA trace for it, perhaps. You figure out the ions?

The latter makes Fe₂O₃ .nH₂O . At compositions between you might be able to get Fe₃O₄ , which is a mixed-oxidation state adduct. The last one is useful since it is ferromagnetic, if I recall. Audio recording tapes were at one time coated with it. A long time ago (1960's-70's).

-- Cheers, --Mr. d.