DraconicAcid
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Copper(II) Anthranilate.....red??
So, a couple of years ago, I introduced a new lab to my students- quantitative analysis of copper by precipitation with anthranilate (as I mention
here: http://www.sciencemadness.org/talk/viewthread.php?tid=45838#... ).
The other day, I was looking at the students' products, and one of them had some lovely little dark red crystals in with the green copper(II)
anthranilate. WTF?
Possibly a nitrosobenzoic acid derivative? I haven't tried picking any of them out to find out what they are yet, but suggestions of possibilities
are welcome. The solutions of sodium anthranilate aren't exactly fresh, so some of the anion may have oxidized, but the copper salts were pure (so it
shouldn't contain some other metal).
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Amos
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Sounds like oxidized anthranilic acid crystallizing with a small amount of its oxidized products in tow.
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Boffis
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Some Cu(I) complexes of colourless organic ligands are red or violet so maybe as Amos suggests the anthranilate portion has been oxidized to something
and the copper reduced accordingly.
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Amos
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I was just referring to air oxidation or impurities already contained in the material; I've seen impressive reddish-brown crystals of anthranilic acid
posted here and in other amateur scientific communities before multiple times. But I won't completely discount the possibility of copper(I) formation.
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DraconicAcid
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I'll have the samples back on Monday- only one of them had the red crystals. I'll check to see if they are soluble in alcohol.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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DraconicAcid
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Posts: 4278
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Follow-up: A bit of alcohol washed the red crystals away easily, so they were merely oxidized anthranilic acid.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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