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Author: Subject: How can I test for Hydroxylamine
guy
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[*] posted on 10-3-2007 at 22:44
How can I test for Hydroxylamine


I attempted to make hydroxylamine and I have a solution and I want to test for hydroxylamine.
Any suggestions?
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GhostofUnintentionalChaos
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[*] posted on 11-3-2007 at 00:09


Depends what your procedure was.
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[*] posted on 11-3-2007 at 03:24


Someone long ago poste this at the Hive.............solo

Read more here (http://www.cem.msu.edu/~reusch/VirtualText/amine1.htm)

Edited: Noted the comment by Unionised .....i just had been working on testing for amines and as it happens I misread the question, hence I retract my suggestion.......and offer,

THE PRODUCTION OF HYDROXYLAMINE BY THE REDUCTION OF NITRATES AND NITRITES BY VARIOUS PURE CULTURES OF BACTERIA'
GLEN A. LINDSEY AND CHESTER M. RHINES



Excerp

The test used for detecting small amounts of hydroxylamine
was the same as the one used by Blom, except that dimethylalpha-
naphthylamine was substituted for alpha-naphthylamine
in accordance with the suggestion of Wallace and Neave (1927).
The necessary reagents are as follows:
(1) 10 grams sulfanilic acid dissolved in 1000 cc. of 5 N acetic acid
(2) 6 cc. dimethyl-alpha-naphthylamine dissolved in 1000 cc. of 5 N acetic
acid
(3) 1.3 grams iodine dissolved in 100 cc. glacial acetic acid
(4) 2.5 grams NavS%Q- 5H20 dissolved in 100 cc. of water

...........then, read the study.


[Edited on 11-3-2007 by solo]




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unionised
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[*] posted on 11-3-2007 at 05:04


Am I missing something, or does that post have practically nothing to do with the question?
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guy
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[*] posted on 11-3-2007 at 13:22


Thanks solo, but those reagents seem hard to obtain.

Can I do a simpler thing like see if it reduces copper or something?
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[*] posted on 11-3-2007 at 14:28


Formation of an oxime derivative from a carbonyl is a common use for hydroxylamine. The melting point of the oxime is then used as a way to confirm the identity of the carbonyl compound. Why couldn't you do this in reverse. Say react your hydroxylamine with acetone or cyclohexanone and then determine the melting point of the crystalline derivative. For the acetone this would be 60C, for the cyclohexanone derivative, 91C.

Also see Vogel's 3rd, p. 1062, where there is a color test using hyroxylamine, an ester, and ferric chloride.

[Edited on by Magpie]

[Edited on by Magpie]




The single most important condition for a successful synthesis is good mixing - Nicodem
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GhostofUnintentionalChaos
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[*] posted on 11-3-2007 at 18:13


From Wikipedia:

Oximes can be synthesized by condensation of an aldehyde or a ketone with hydroxylamine. The condensation of aldehydes with hydroxylamine gives aldoxime, and ketoxime is produced from ketones and hydroxylamine. Generally, oximes are colorless crystals and do not dissolve into water easily. Therefore, oxime is used for the identification of ketone or aldehyde.

Do use the idea of the test backwards as a test for hydroxylamine.
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guy
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[*] posted on 11-3-2007 at 19:19


Apparently acetoxime is pretty soluble in water and I might have made that. I'll try and rehydrolyse that. Would MEK be a better test?
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[*] posted on 11-3-2007 at 19:45


My book says that the oxime of MEK is an oil, and that is why I didn't suggest it.

You should also be able to make hydroxylamine hydrochloride. I don't know its melting point. I know it is a white crystal as I bought some.

If you want I can provide the procedure from my book for making acetoxime from acetone. It's not too lengthy.

[Edited on by Magpie]




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[*] posted on 11-3-2007 at 20:05


Ok thanks, Magpie.
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[*] posted on 11-3-2007 at 20:24


From Unitized Experiments in Organic Chemistry,by Brewster et al, p.73:

"A. Acetoxime. Dissolve 0.7g of hydroxylamine hydrochloride in 1.5 mL of water in a small Erlenmeyer flask. Place the flask in an ice bath and add slowly a cold solution of 0.5 g of sodium hydroxide in 1 mL of water. Then, with the flask still in the ice bath, add slowly 1 g (25 drops) of acetone (Note 1). The crystals of acetoxime will separate completely within 10-15 minutes (Note 2). Then filter the crystals (Note 3) by means of a small Hirsch or Buchner funnel, and recrystallize from petroleum ether (bp 40-60C). Dry rapidly on filter paper (Note 4) or in a desiccator and determine the melting point."

"Notes:

1. If the unknown does not dissolve completely or if the solution is turbid at this point, add just enough 95% alcohol to give a clear solution.
2. [bullshit not germane to this procedure]
3. If no solid separates on cooling add 3 volumes of water and cool again.
4. Acetoxime has a rather high vapor pressure and evaporates readily in air."




The single most important condition for a successful synthesis is good mixing - Nicodem
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[*] posted on 11-3-2007 at 21:09


Hmmm. When I added acetone to my solution I did get an immediate precipitate but I thought that was just NaCl precipitating out.
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GhostofUnintentionalChaos
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[*] posted on 11-3-2007 at 21:57


If they are supposed to seperate within 15 minutes, it probably was NaCl. If you saved the crystals, you could test those by drying and warming for an extended period of time and checking for change in mass (other than water and acetone evaporating off). What other impurities could be expected in solution other than NaCl?
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[*] posted on 11-3-2007 at 23:41


Probably sodium sulfate.

I tried making my own potassium nitrite and I added that to sodium bisulfite at 0oC. I added HCl to hydrolyse the intermdiate and heated that for about one 12 hrs. During the course, lots of cubic NaCl precipitated. I added some acetone and immediately a white precipitate formed. I thought it was NaCl so I threw it out.

I'll probably do the whole experiment over later.
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