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AJKOER
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Aga:
Actually, there is more value in my comment than simply proceeding without HNO3. The nature of some of the unexpected results may disappear in a
nitrite approach.
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Since you mentioned experimenting, I just finish exploring the wonders of weakened gamma alumina/Al on a solution of royal blue copper ammonium
hydroxide (prepared by the action of dilute H2O2 on Copper in aqueous household ammonia with some sea salt, an amazing rapid formation of the royal
blue complex with a moment of sigificant bubbling from associated NH4NO2 decomposition).
The original royal blue transforms in 10 minutes to aqua blue and then clear upon the addition of the gamma weakened alumina/Al!
Talk about experimenting!
I suspect the formation of copper aluminate which breakdowns in solution leaving copper ions and Aluminum ions!!
Interestingly, if one dilutes the solution with distilled water, some color returns!
-------------------------------------
Sorry for the theory session on this thread, but I once worked with Lead salts and have since lost the desire to work with them further. This was more
psychological than real as my brothers kids spent some time in Chile and returned to the USA with learning disabilities that slowly cleared up over
years. I suspect heavy metal exposure to their developing minds when in Chile. Just scary stuff.
[Edited on 30-6-2014 by AJKOER]
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blogfast25
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Quote: Originally posted by AJKOER  | Since you mentioned experimenting, I just finish exploring the wonders of weakened gamma alumina/Al on a solution of royal blue copper ammonium
hydroxide (prepared by the action of dilute H2O2 on Copper in aqueous household ammonia with some sea salt, an amazing rapid formation of the royal
blue complex with a moment of sigificant bubbling from associated NH4NO2 decomposition).
The original royal blue transforms in 10 minutes to aqua blue and then clear upon the addition of the gamma weakened alumina/Al!
Talk about experimenting!
I suspect the formation of copper aluminate which breakdowns in solution leaving copper ions and Aluminum ions!!
Interestingly, if one dilutes the solution with distilled water, some color returns!
[Edited on 30-6-2014 by AJKOER] |
This is for the most part just gobbledygook, as we've come to expect from you. No evidence presented, unsubstantiated claims made, contentious terms
used.
Explain it step by step and people might get interested.
[Edited on 30-6-2014 by blogfast25]
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aga
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I think i have to agree with blogfast25.
Flapping about and waving an ammony-wand doesn't really engage anything with me at least.
It really would be far more interesting to see your detailed examination of tinfoil heated on a candle, then doused with OTC 3% ammonia, and some 3%
OTC peroxide added, and a pinch of salt.
The hypothesis, equations, reactants (source, purity, possible contaminats etc), method, observations, conclusions ... you know, like a real
scientific experiment, which would enable others to duplicate the experient and check the conculsions.
No matter if it is tinfoil and table salt : there is no shame in having impure reactants, so long as you Know that, state that, and maybe have some
clue as to what the impurities are.
What is 'The' Royal Blue complex ?
I made some tetraamminecopper(II)sulfate early on, and that's a deep, rich, regal purply-blue ...
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blogfast25
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| Quote: Originally posted by AJKOER |
I suspect the formation of copper aluminate which breakdowns in solution leaving copper ions and Aluminum ions!!
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... for instance make no sense at all. As AJ should know well by now aluminate anions (Al(OH)<sub>4</sub><sup>-</sup> can only exist in conditions of high pH (at least at reasonable concentrations). At
such pH values solvated Cu<sup>2+</sup> cannot exist and will precipitate as Cu(OH)<sub>2</sub> (hydrated). At very high pH
values aluminate and copper (II) could coexist with the copper as the cuprate ion (Cu(OH)<sub>4</sub><sup>-</sup>.
I see no regime in which 'copper aluminate' can exist, either in solution or as a pure substance (precipitate). No to mention conditions in which the
mysterious 'copper aluminate' would "breakdowns in solution leaving copper ions and Aluminum". The exclamation marks would be well deserved...
[Edited on 30-6-2014 by blogfast25]
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AJKOER
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Two points if I may. First, it should be easy to replicate my observation. Create a royal blue tetraamminecopper complex under alkali conditions
(alkali per one of the half reaction in the electrochemical part of the reaction of Cu, H2O2, NH3 with sea salt as the preferential electrolyte, as a
reference please see "Kinetics and Mechanism of Copper Dissolution In Aqueous Ammonia" fully available after signing on to ones Facebook account at http://www.academia.edu/292096/Kinetics_and_Mechanism_of_Cop... ). Next, burn to glowing red Aluminum foil to form, my contention based on
chemical reactivity, weakened gamma Al2O3 and Al (reference, see white paper at https://www.google.com/url?sa=t&source=web&rct=j&... ).
Second, I am speculating on the chemistry, no references on this reaction (except perhaps http://www.sciencemadness.org/talk/viewthread.php?tid=20554 ). Combine with the tetraamminecopper complex and watch, it doesn't take long. What is
evident is the gradual and complete break up of the royal blue tetraamminecopper complex and the formation of a clear, I suspect Aluminum, sallt.
[Edited on 1-7-2014 by AJKOER]
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aga
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It would be easier for a total noob like me to have a detailed procedure to follow, showing exactly what the reactants are and what you do with them.
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blogfast25
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Aga:
As a first step, mix some copper conductor wire (fine strands cut into pieces), some NaCl, some peroxide solution and some ammonia. Mix to dissolve
the NaCl. Allow to stand and observe.
With both an oxidiser AND a complexing agent present, some copper is likely to dissolve, to dark blue copper (II) tetrammine complex. It's a 'going
round the houses' way of preparing a bit of the latter.
Then we'll see.
Aluminium is notoriously difficult to burn due to that passivation layer that protects it against further attack.
I suspect AJ's solution loses colour simply because the copper (II) tetrammine complex is reduced to copper by the aluminium. Nothing mysterious... or
new. It's known (there's a good thread about it somewhere) that that reduction can be very fast in the presence of chloride ions.
[Edited on 1-7-2014 by blogfast25]
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AJKOER
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| Quote: Originally posted by blogfast25 | Aga:
As a first step, mix some copper conductor wire (fine strands cut into pieces), some NaCl, some peroxide solution and some ammonia. Mix to dissolve
the NaCl. Allow to stand and observe.
With both an oxidiser AND a complexing agent present, some copper is likely to dissolve, to dark blue copper (II) tetrammine complex. It's a 'going
round the houses' way of preparing a bit of the latter.
Then we'll see.
Aluminium is notoriously difficult to burn due to that passivation layer that protects it against further attack.
I suspect AJ's solution loses colour simply because the copper (II) tetrammine complex is reduced to copper by the aluminium. Nothing mysterious... or
new. It's known (there's a good thread about it somewhere) that that reduction can be very fast in the presence of chloride ions.
[Edited on 1-7-2014 by blogfast25] |
Blogfast:
I cannot fault your logic as it was mine first!
My intention of performing the experiment was a quick and inexpensive path to fine copper.
However, as copper or its oxide is not visibly formed, it may have dissolved into some colorless(?) compound under alkali conditions. Aluminum also
has apparently entered the solution.
To speculate further is clearly way off the topic of this thread.
---------------------------------
Here is a good reference on electrochemistry that at times includes Pb. See http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch20/el...
[Edited on 1-7-2014 by AJKOER]
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Zyklon-A
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| Quote: Originally posted by aga | Er, Jokey A ?
Do you get your kicks out of randomly Googling chem stuff in order to respond to someone actually Doing some chemistry, or is it a Kick just to get
some random chemist (as in an Actual Chemist) responding to to the stuff you've just googled ? |
Who cares if he does that? I google things all the time and use the information I just learned to reply to posts. Lots of people here do that.
There's no reason to do an experiment for every question you have, and you'll learn a lot more from looking up actual scientific sources then any
experiment. The reason is simple, when you do an experiment, there is so much room for error just from inaccurate measurements, impure
reagents, wrong stoichiometry, different reactions happening than expected etc.
| Quote: Originally posted by aga |
What is with the ammonia gig anyway ?
It's a chemical, yes, loosely bridging OC and IOC (in my mind at least), but nothing more.
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Ammonia is a pretty cool chemical. You saying that it's unimportant simply because you haven't used it much, only makes you look ignorant and
arrogant.
| Quote: Originally posted by aga |
Chemistry, to me, is Exploring the Theoretical, then Testing by Experiment.
Not Einstein's cheapskate Thought Experiments, but by Actual Experiments, to see what Actually happens. |
Or you could just read a paper that has all the information you need and save you a lot of time. Then you can spend your time doing reactions that
benefit you in some way (like teaching you, or synthesizing a new, useful reagent (like ammonia ) )
| Quote: Originally posted by aga |
You seem to be fixated on doing No experiments, and simply Googling to elicit any kind of response. |
Again, who cares? Maybe he dosn't have time to do experiments. Maybe he doesn't need to, cause he can find all the information he needs online.
He is contributing. Have you ever even followed the references he sites? I do, they are full of very relevant information generally.
So, instead of complaining about what he does post, why don't you try to learn something from it?
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aga
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If you do an experiment yourself, you learn much, especially when it goes totally wrong.
I can't see where i say 'ammonia is unimportant', most likely cos i didn't say that at all.
NH3 is pretty cool, i agree, and making it i has been great fun the 5 and only times i have done so, especially when it went totally wrong
the first time ...
At my 3-months-in level of learning, much of the published info is way over my head, fascinating though it is.
I agree that AJ's references are well worth reading, and i cannot remember one that was boring.
My boggle is basically the vagueness.
I can't mix 'vaguely some' gamma Fluffitol with a half-quoundle of Amoonyflip and even imagine to repeat the experiment accurately.
The last time AJ actually wrote down a do-able reaction, i did 5 of them, and reported the findings.
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blogfast25
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| Quote: Originally posted by AJKOER | [However, as copper or its oxide is not visibly formed, it may have dissolved into some colorless(?) compound under alkali conditions. Aluminum also
has apparently entered the solution.
|
There are no colourless, aqueous Cu(II) compounds, even less so when chloride and/or ammonia is present, alkaline or neutral.
The fact that the solution became colourless points to reduction of the Cu(II) to copper, it's the only reasonable way to explain the loss of blue.
The initial solution may have contained very little Cu(II) to begin with, as a the tetrammine complex is very intensely coloured and very small
amounts will cause colouration (and the dissolution of copper metal in saline, peroxydic ammonia cannot be a fast process). If so, the amounts of
reduced copper may be hard to see.
Al would have entered the solution as unburned Al reduced Cu(II) to copper, the Al being oxidised to Al(III).
There is in essence nothing to see here...
[Edited on 1-7-2014 by blogfast25]
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blogfast25
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| Quote: Originally posted by Zyklon-A | [ He is contributing. Have you ever even followed the references he sites? I do, they are full of very relevant information generally.
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Sorry, but he also posts a lot of irrelevant, obscure and sometimes demonstrably faulty stuff too. AJ's a champ for cherry picking material that
seems to confirm his ideas, even if the sources are far from credible. On other occasions he pulls things horribly out of context.
He's posted references to 'nascent hydrogen' for instance. I could go on.
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AJKOER
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Yes, true, and here are the details on hydrogen formed on an Aluminum surface as published in a 2012 prestigious journal, link http://www.researchgate.net/publication/221934434_Chemical_r... , titled "Chemical reduction of an aqueous suspension of graphene oxide by nascent
hydrogen" by Viet Hung Pham, Hai Dinh Pham, ... in Journal of Materials Chemistry (Impact Factor: 5.97). 05/2012; DOI:10.1039/C2JM30562C .
To quote from the abstract:
"ABSTRACT One of the major challenges in the chemical reduction of graphene oxide is increasing the C/O atomic ratio of the chemically-converted
graphene. In this paper, we report a simple and effective method to reduce aqueous suspensions of graphene oxide using nascent hydrogen generated in
situ by the reaction between Al foil and HCl, Al foil and NaOH and Zn powder and NaOH. The nascent hydrogen-reduced graphene oxides (nHRGOs) were
characterized by elemental analysis, UV-vis spectra, Raman spectra, X-ray photoelectron spectroscopy, thermogravimetric analysis and electrical
conductive measurements. The reduction efficiency of graphene oxide strongly depended on the reaction medium and the rate of nascent hydrogen
generation. The best nHRGO achieved a C/O atomic ratio greater than 21 and a bulk electrical conductivity as high as 12,500 S/m, corresponding to the
nascent hydrogen generated from the reaction between Al foil and HCl. Since nascent hydrogen could be produced on a metal surface upon oxidation in
solution, other metals with low standard reduction potentials, such as Mg, Mn, and Fe, can be applied to reduce graphene oxide."
The reason this article was published, in my opinion, relates to its value as a potential source of graphene.
For some background on why graphene is potentially important, see for example, http://www.telegraph.co.uk/finance/businessclub/10936423/Gra...
By the way, I for one, do not include the Journal of Materials Chemistry in the group of "sources are far from credible". However, when I do quote
Atomistry.com as a source, beware, as it contents, per a recent discovery of mine, are extracts taken from noted journals of the time with, however,
references deleted and no supplied date of publication.
[Edited on 2-7-2014 by AJKOER]
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arkoma
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How many times does poor aga have to say,"I am a n00b, please 'dumb it down' for me so I can get a handle"? Talk about arrogant pricks...............
EDIT-if no one has noticed, this is BEGINNINGS
[Edited on 7-2-2014 by arkoma]
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
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blogfast25
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| Quote: Originally posted by arkoma | How many times does poor aga have to say,"I am a n00b, please 'dumb it down' for me so I can get a handle"? Talk about arrogant pricks...............
EDIT-if no one has noticed, this is BEGINNINGS
[Edited on 7-2-2014 by arkoma] |
Totally uncalled for.
Not everyone who posts in beginnings is a beginner either.
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blogfast25
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| Quote: Originally posted by AJKOER | However, when I do quote Atomistry.com as a source, beware, as it contents, per a recent discovery of mine, are extracts taken from noted journals of
the time with, however, references deleted and no supplied date of publication.
[Edited on 2-7-2014 by AJKOER] |
Which is essentially an act of plagiarism.
I've also found atomistry.com demonstrably wrong in one of their entries. An interesting and useful site but take content with a pinch of salt.
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