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rka
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[*] posted on 26-5-2017 at 23:20
chemistry


How to, chemically and not electrolytically, get Ag from AgSCN powder?
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PirateDocBrown
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[*] posted on 26-5-2017 at 23:57


Heat.
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AJKOER
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[*] posted on 27-5-2017 at 04:20


Boiling AgCl in aqueous sugar is frequently performed (I have done it successfully a few years ago) to retrieve metallic Silver. This may provide a path here, but be wary of products produced and disposal issues thereof.

Please note, not all sugars are equally effective in this reaction! See discussion at https://www.finishing.com/195/29.shtml .
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27-5-2017 at 05:04
Eddygp
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[*] posted on 31-5-2017 at 07:44


Can anyone point me in the direction to find some literature about glutamate dehydrogenase inhibitors? I haven't been able to find anything so far.



there may be bugs in gfind

[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
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Alice
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[*] posted on 31-5-2017 at 08:38


google scholar: glutamate dehydrogenase inhibitor / inhibition. Gives various hits. Or are you looking for something specific?
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[*] posted on 1-6-2017 at 11:55


There was a thread/discussion on the board somewhere or other regarding seperation of sodium chlorate from sodium perchlorate using acetone. It was mostly figured out by (I think) Hennig Brand.
Can someone link me to the thread. I simply CANNOT find the thing.

Thanks,
Yob
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[*] posted on 3-6-2017 at 03:00
Element mirrors


The silver mirror (Tollen's reagent) is very well known.
I am interested in attempting the same thing with different elements. I have heard that something similar can be done with copper using hydrazine as a reducing agent.

I was wondering if anyone had any experience with mirroring other elements. Specifically bismuth.

J.
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Plunkett
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[*] posted on 5-6-2017 at 04:07
Question


Around what concentration does sulfuric acid cease to be an effective drying agent? More specifically, can my drain cleaner sulfuric acid (~93%) be used to dry bromine?
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[*] posted on 5-6-2017 at 11:47
Question.


Today was making a solution of copper (II) chloride via mixing a 1:1 ratio of HCl and 3% H2O2 and adding that to copper. I have done this before but I had a little bit of a different result this time. I left it for around two hours and it soon became this dark brown liquid. I tested it by adding a few drops to aluminum and it made the famous vigorous reaction between CuCl2 an Aluminum. I also dilluted a small sample and it turned into an olive green color.
My guess on what it is is a saturated solution of copper (ii) chloride or that it's just really contaminated with copper (i) chloride. What chemical do I have here???
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[*] posted on 5-6-2017 at 13:13


question

hi,so i just rewatched nurdrage's video for making luminol and i was wondering what exctly happens when he mixes aluminium and sodium metabisulfite?does it form sodium dithionite in situ? or is it something else.
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[*] posted on 5-6-2017 at 13:45


Quote: Originally posted by TheNerdyFarmer  
Today was making a solution of copper (II) chloride via mixing a 1:1 ratio of HCl and 3% H2O2 and adding that to copper. I have done this before but I had a little bit of a different result this time. I left it for around two hours and it soon became this dark brown liquid. I tested it by adding a few drops to aluminum and it made the famous vigorous reaction between CuCl2 an Aluminum. I also dilluted a small sample and it turned into an olive green color.
My guess on what it is is a saturated solution of copper (ii) chloride or that it's just really contaminated with copper (i) chloride. What chemical do I have here???


I think the dark brown is either the tetrachlorocuprate(II) ion, or a complex ion containing both copper(I) and copper(II).




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TheNerdyFarmer
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[*] posted on 5-6-2017 at 13:54


Is there any way to know the percent of copper ii chloride so I can try and extract it?.
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[*] posted on 5-6-2017 at 14:22


Quote: Originally posted by TheNerdyFarmer  
Is there any way to know the percent of copper ii chloride so I can try and extract it?.

If you dilute it sufficiently, any copper(I) chloride should precipitate.




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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[*] posted on 7-6-2017 at 10:00
Determinig KCl vs NaCl solution - easy way to differentiate?


Is there any way to test a solution to see if it is sodium or potassium chloride
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[*] posted on 7-6-2017 at 10:31


A flame test is a good way to distinguish, if it is pure. A wooden splint dipped in KCl solution and held in a flame will give a light purple color, while an NaCl solution will give a bright yellow-orange color. The presence of sodium will cover up the color from potassium though, so it isn't perfect.

Another way that comes to mind is that some potassium salts are much less soluble than their sodium analogues, such as with chlorate and perchlorate. So if you happened to have some sodium chlorate, you could add some of your solution to a reasonably concentrated solution of it and see if you get a precipitate.




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[*] posted on 7-6-2017 at 12:02


Quote: Originally posted by zts16  
A flame test is a good way to distinguish, if it is pure. A wooden splint dipped in KCl solution and held in a flame will give a light purple color, while an NaCl solution will give a bright yellow-orange color. The presence of sodium will cover up the color from potassium though, so it isn't perfect.

Another way that comes to mind is that some potassium salts are much less soluble than their sodium analogues, such as with chlorate and perchlorate. So if you happened to have some sodium chlorate, you could add some of your solution to a reasonably concentrated solution of it and see if you get a precipitate.


Thank you, the flame test should be sufficient to verify what the solution is as it should be a pure solution (99%+ purity of original salt mixed with distilled water). Thanks again!
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[*] posted on 7-6-2017 at 12:32


Quote: Originally posted by zts16  
A flame test is a good way to distinguish, if it is pure. A wooden splint dipped in KCl solution and held in a flame will give a light purple color, while an NaCl solution will give a bright yellow-orange color. The presence of sodium will cover up the color from potassium though, so it isn't perfect.

Another way that comes to mind is that some potassium salts are much less soluble than their sodium analogues, such as with chlorate and perchlorate. So if you happened to have some sodium chlorate, you could add some of your solution to a reasonably concentrated solution of it and see if you get a precipitate.


well I took a long wooden match stick, dipped it into the solution and put it into the blowtorch flame. I had 2 known (NaCl and KCl) solutions and an unknown. the NaCl gave a nice yellow/orange flame almost as if I was adding an accellerant to the flame. If put at the base of the flame, the length of the flame turned yellow/orange. When I did the KCl I still got a similar flame, but it didn't seem as "energetic" - if that makes sense, it woulnd't propagate the flame the same way when placed at the base (all solutions are super-saturated at room temp).

The unknown does look more similar to the KCl but it is not a purple flame except maybe a couple mm immediately off the match stick.

The purple wasn't easily noticable in the known KCl solution as they all gave a yellow orange flame but the NaCl never produced the small purple near the wood.

Is this the results I should expect? I was concerned that maybe the wood was a little different to give the purpleish color.

The sodium flame was impressive though!
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[*] posted on 7-6-2017 at 12:45


The trouble with the flame test is that soooo many things are contaminated with just enough sodium to overpower the other colours. A common trick in the old days (when people relied on the test) is to view the flame through didymium welder's glass, which blocks out the yellow quite selectively. Or using a platinum wire instead of a wooden stick.



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[*] posted on 7-6-2017 at 18:17


first find something to hold your sample in the flame which does not itself give a yellow flame ... surprisingly difficult.
Nichrome resistance wire works ok, I think nickel spatulas but I'm not sure,
carbon often gives a similar yellow.

even then, if the 1% impurity is sodium (quite possible) then it may be enough to show as sodium.

I have tried borax bead tests, if I have nothing else to do I may re-visit .... useful but tedious.
https://en.wikipedia.org/wiki/Bead_test





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Texium (zts16)
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[*] posted on 7-6-2017 at 19:14


Even so, if his sample was sodium chloride, or contained a substantial amount of it, it would have been very obvious. I think it's safe to conclude that the unknown is KCl, assuming that it could either be NaCl or KCl, and not anything else.



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[*] posted on 7-6-2017 at 19:42


true,

I just thought that the borax bead test was worth mentioning

(plus, I was showing off the entire extent of my knowledge in this area :P




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[*] posted on 10-6-2017 at 19:49


@RogueRose

If you are really desperate, make a sodium cobaltinitrite solution. Potassium cobaltinitrite is insoluble in water and will precipitate out, while sodium cobaltinitrite won't. But it may contaminate the potassium chloride solution, so perform this test in a separate reaction vessel.

[Edited on 6-11-2017 by ninhydric1]
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[*] posted on 10-6-2017 at 20:51


Question

For a distillation, is it possible to set up a Syphoning system if you don't have a water pump on hand, would this work? I was thinking something like this and just lifting the water at the bottom to the top by hand.

thanks.

PS this is my first time here so yea, sorry if this has already been discussed, although i did look , I could not find anything.

syphoning.png - 6kB
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[*] posted on 10-6-2017 at 21:08


I'd be more inclined to use a regular tap.
A siphon is not going to be a recirculating system unless you babysit it and tip the water back into the top bucket.
Also, the flow-rate will diminish as the had decreases.
It just all seems awkward. Either spend $20 bucks on a pond pump or plan on flushing some water down the drain.
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[*] posted on 11-6-2017 at 02:13


A syphon is certainly a way to cool a condensor. The flowrate can be easily adjusted by raising the upper basin. This allows you to control the temperature of the output quite precisely. As has been said above you need to baby-sit this setup and be prepared to reestablish the syphon several times per run. Aquarium pumps are the way to go.
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