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DraconicAcid
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Quote: Originally posted by unionised  | | Is it just my imagination, or is this a rather long thread to see if someone has silver iodide (which is yellow) or copper iodide (which is white)?
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CuI is only white when it's pure. Some of us often get off-white products which were supposed to be white.
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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| Quote: Originally posted by DrMario |
It clearly exists for a while - the reaction where 2CuI2 --> 2CuI + 2I is relatively slow. You should try it, it's educative.
Now the fact that the OP does not have CuI2 because of its instability, is another question. Etc. |
I have done the reaction, and while there is a transient yellow colour, that could easily be due to a CuI+ complex or other species. Or
dilute triiodide ion, or....
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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DrMario
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| Quote: Originally posted by DraconicAcid | | Quote: Originally posted by DrMario |
It clearly exists for a while - the reaction where 2CuI2 --> 2CuI + 2I is relatively slow. You should try it, it's educative.
Now the fact that the OP does not have CuI2 because of its instability, is another question. Etc. |
I have done the reaction, and while there is a transient yellow colour, that could easily be due to a CuI+ complex or other species. Or
dilute triiodide ion, or.... |
Okay.
BTW, this text (with no actual corroboration except for "yeah, it makes some sense, why not...." states that cupric iodide can be stabilized with
ammonium complexation:
http://copper.atomistry.com/cupric_iodide.html
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DraconicAcid
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Well, what do you think the blue colour we've been talking about is? The blue colour is the tetramminecopper(II) ion, and the iodide counterions are
still there in solution with it.
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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DrMario
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"Blue" (with its myriad hues) could very well be a colour of a hypothetical CuI2-ammonium ion complex. I don't know that that's not possible.
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