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Talk:Chromite (compound)

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Formula

[edit]

The formula for a chromite is needed... --Chemicalinterest (talk) 17:52, 15 June 2010 (UTC)[reply]

Done! --Chemicalinterest (talk) 13:31, 16 June 2010 (UTC)[reply]

Chromous acid

[edit]

Chromous acid is not entirely hypothetical.

I don't know if Cr(OH)3 (i.e. H3CrO3) has ever been detected, but remove H2O from the formula and you have HO-Cr=O, i.e. HCrO2, which is better known as chromium(III) oxide hydroxide, CrO(OH), grimaldiite. This is a stable mineral whose crystal structure has been determined many times.

Ben (talk) 17:47, 16 June 2010 (UTC)[reply]

Has this been characterized as chromous acid, then? As in, it can be deprotonated to form salts containing CrO
2
?—Tetracube (talk) 19:13, 16 June 2010 (UTC)[reply]
Hmm, need some help here. Does the CrO
2
ion actually exist as a distinct anion (either in crystal or in solution)? Or is it merely a simplification from earlier work when the nature of the hydrated complex Cr(OH)3−
6
is not yet known? I'm wondering because the article currently states that sodium chromite is a salt of HCrO
2
, but then proceeds to display an equation involving Na
3
Cr(OH)
6
. Also, I noticed that in the literature sodium chromite is written both as NaCrO
2
and Na
3
Cr(OH)
6
. What is the "real" formula for sodium chromite? Or are these the same salt hydrated to different extents?—Tetracube (talk) 19:48, 18 June 2010 (UTC)[reply]