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Author: Subject: The Short Questions Thread (4)
mayko
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[*] posted on 7-1-2019 at 09:24


When I harvest lithium foil from batteries, I try to store it under mineral oil, but between its low density and entrained bubbles, it floats to the top. I could probably add paperclips and a weight or something to keep it submerged, but I wondered if anyone else had protips?



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[*] posted on 7-1-2019 at 10:10


Quote: Originally posted by mayko  
When I harvest lithium foil from batteries, I try to store it under mineral oil, but between its low density and entrained bubbles, it floats to the top. I could probably add paperclips and a weight or something to keep it submerged, but I wondered if anyone else had protips?


I think it would float even without bubbles. Try less dense inert liquid or put something heavy (also inert) on top.

You could also store it in inert gel, or even solid. (maybe paraffin wax) not sure about compatibility, so research.




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ninhydric1
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[*] posted on 7-1-2019 at 20:50


I know MrHomeScientist ampouled some lithium metal in an inert atmosphere, which eliminates the density issue entirely.



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C6(NO2)5CH2CH(CH3)N(NO2)2
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[*] posted on 14-1-2019 at 15:33
what will precipitate first? Calcium hydroxide or ammonia gas?


I have been wondering if you can produce ammonia and a calcium salt from hydrated lime and an ammonium salt. According to this post: http://www.sciencemadness.org/talk/viewthread.php?tid=7464&a... You can add calcium hydroxide to ammonium chloride to produce ammonia 2NH4Cl+Ca(OH)2-->CaCl2+2NH3+ 2H20. I'd assume that this reaction would go in this direction due to all the different ions being in solution, and the unstable combination (NH4OH) decomposing and "precipitating" ammonia gas. But in this post: https://www.sciencemadness.org/whisper/viewthread.php?tid=83... it says that you can make ammonium nitrate out of calcium nitrate by adding ammonia solution: 2NH4OH+Ca(NO3)2-->2NH4NO3+Ca(OH)2. I suppose that makes sense that the calcium hydroxide would precipitate too, since it is poorly soluble in water (unlike ammonium nitrate) But it also means that adding the calcium hydroxide to an ammonium salt would probably fail to produce any reaction.

So I guess my question is this: Which compound comes out of solution first? and (sorry if this is spoonfeeding) if you hypothetically added calcium hydroxide to a saturated solution of Calcium nitrate-ammonium nitrate double salts, would I get calcium nitrate and ammonia vapor, or would nothing happen? or would it be a partial reaction, and the calcium hydroxide would stop dissolving prior to all the ammonium nitrate being converted?

[Edited on 14-1-2019 by C6(NO2)5CH2CH(CH3)N(NO2)2]




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[*] posted on 14-1-2019 at 19:13
purple zinc chloride


I discovered today that I don't have any zinc chloride. Never mind I thought. I have some zinc from a D cell and plenty of hardware-store HCl of reasonable purity.
After reacting, the resultant solution was a purple/lilac colour. Berating myself, I concluded that stray manganese dioxide from the battery was the most likely culprit. So I repeated with some reagent grade zinc powder.
Same result. It must be some impurity in the HCl. But what? I know that Fe is common but I have tested the acid for Fe in the past with a negative result. Is Mn or Co likely?

[Edited on 15-1-2019 by j_sum1]

2019-01-15 13.12.19.jpg - 313kB
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clearly_not_atara
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[*] posted on 14-1-2019 at 20:11


^Also, solutions of iron chloride are brown.

The HCl itself isn't colored, but with zinc it is? If it were a simple metal chloride the addition of zinc should not change the color. Mn or Co will be present as the divalent salt which should not undergo any sort of redox in this condition.

However, maybe the HCl is a little greenish? That would indicate chromium, as CrCl3 gives a green solution and CrCl2 a blue one. Additionally various aqua-chloro chromium complexes are slow to interconvert and have many different colors.




[Edited on 04-20-1969 by clearly_not_atara]
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clearly_not_atara
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[*] posted on 29-1-2019 at 01:07


I noticed that the reaction:

N2 + 5/2 O2 + 2 KOH >> 2 KNO3 + H2O

has ΔH = [2 * -494] + [-285] - [2 * -426] = -421 kJ/mol

Is it possible to induce this reaction somehow?




[Edited on 04-20-1969 by clearly_not_atara]
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walruslover69
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[*] posted on 29-1-2019 at 05:42


I can't imagine you would be able to on a small scale. You would probably need a really specialized catalyst. That nitrogen triple bond has a huge activation energy.

I am really surprised how favorable the reaction is though.

[Edited on 29-1-2019 by walruslover69]
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[*] posted on 29-1-2019 at 14:04


I am wondering if anyone can suggest a way to remove a palladium chloride stain from a glass frit. I have tried conc. HCl acid which has reduced the discoloration by approx. 80% however 80% is still not complete. Any suggestions would be appreciated as the funnel was brand new. Thanks .
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[*] posted on 29-1-2019 at 15:19


Quote: Originally posted by SHADYCHASE54  
I am wondering if anyone can suggest a way to remove a palladium chloride stain from a glass frit. I have tried conc. HCl acid which has reduced the discoloration by approx. 80% however 80% is still not complete. Any suggestions would be appreciated as the funnel was brand new. Thanks .


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[*] posted on 9-2-2019 at 01:04
3,4,5-Trimethoxyben?


Hey chemoforumers,

Purchased some 3,4,5-trimethoxybenzaldehyde from a (seemingly) reliable source, however, I have my doubts. Material appears as white flakes/granules. very hard and brittle, and doesn't seem to have any real smell.

I would have expected the compound to have very different physical properties, as similiar subst benzaldehydes (vanillin, 5-bromovanillin, syringaldehyde) have very strong smells and form fine , non-brittle crystals. This might seem obsesive, but want to be sure I have the right stuff;) .

Anyone familliar with the substance? Does this sound like 3,4,5-trimethoxy ben, or definitely something else?




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fusso
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[*] posted on 22-2-2019 at 15:12


Some time ago, I heated some sugar to make elemental carbon. The resulting mass is very brittle and won't make black marks on paper, unlike graphite. Is it amorphous C?



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clearly_not_atara
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[*] posted on 22-2-2019 at 15:49


It's called "sugar charcoal".

https://en.wikipedia.org/wiki/Sugar_charcoal




[Edited on 04-20-1969 by clearly_not_atara]
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mayko
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[*] posted on 7-3-2019 at 19:09


I've been reading about molybdenum chemistry, and it seems surprisingly complicated. One pathway I'm interested in trying out would include an oxidation of molybdenum (V) oxytrichloride to molybdenum (VI) trioxide:
MoOCl3 ----????----> MoO3
it's not obvious to me how to do this. I can't find a lot of detail on the oxytrichloride; the book I'm reading says that it decays in cold water, but doesn't give any further information. Any ideas?




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[*] posted on 8-3-2019 at 08:47


I am wondering if someone might have a user manual for Parr pressure vessels pre-magnetic stir drive? I recently aquired a 600ml stirred reactor gland type stirrer however I am finding it quite impossible to source any of the 1980-90 Parr manuals or user guides. Any help would be appreciated.
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[*] posted on 30-3-2019 at 03:47


Another quick question, would anyone have a suggestion regarding a reasonably accurate vacuum gauge with error limit not exceeding (+)(-) 25-40torr. I mean to connect it to a vacuum tank to determine (manual) on off cycles so as to maintain max. vacuum, as it isn't convenient in this circumstance to connect a glass Hg Manometer. I am looking for one that is analog pressure gauge style. The reason i am bothering to ask, what may on the surface appear a dim question, is that my previous purchase turned out to be useless junk. When i tested the vac. gauge and measured for accuracy it was off between 110-118torr. and these values fluctuated considerably. So if anyone has bought an analog vac. gauge that is resonably accurate as well as resonably priced could you please provide a link or a brand/model number I would appreciate it.

As alway thanks for any suggestions.
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[*] posted on 9-4-2019 at 17:36


I've been turning some of my copper collection into copper sulfate, using sulfuric acid + peroxide. I decided to try a less hands-on approach by using an aquarium pump to aerate sulfuric acid, copper, and water in a jug. It's taking longer than I'd expect, but there is also something happening that I just can't wrap my head around. The air bubbling tube has collected several inches of crystal growth *inside the tube*, that is to say, the growth has taken place against the flow of the air, and indeed has plugged the tube at least once. How could this happen? I could believe that a little spray might sometimes make it a little bit up the tube, but surely it would be quickly cleared from the air flow?



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[*] posted on 17-4-2019 at 10:19


Would the reaction of a bromoketone and theobromine actually take place at 1-, on the amide between both carbonyls?
I believe it would due to their directing effect, but I am not sure.
And since I need to isolate the theobromine from cocoa, I will very likely only have a rather tiny amount of it to experiment.
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[*] posted on 17-4-2019 at 17:33


Mayko

I'm guessing that what is happening is that you get capillary flow of the liquid up the tube. Aquarium air pumps are quite gentle so I'm imagining laminar flow with very low flow rates at the walls to counter the capillary action. The air dries the liquid so that you get a smaller diameter tube which increases the capillary action even more. This is as I said a guess :)
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[*] posted on 17-4-2019 at 18:01


Is there am acidic derivative of theobromine called chocolic acid (which would have the conjugate base chocolate)? Why the hell not?



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[*] posted on 20-4-2019 at 23:20


Does acetonitrile react with sodium metal? If so, what are the products of this reaction?
I'm hoping this might be the way to make some sodium cyanide. :D


[Edited on 21-4-2019 by bipolar]
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[*] posted on 24-4-2019 at 00:21


For amide/protein hydrolysis, which one is faster, basic or acidic? (assume base/acid has same initial concentration in both rxns)



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[*] posted on 26-4-2019 at 01:42


Can piranha solution oxidize gold, Pt and other PGMs?



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[*] posted on 26-4-2019 at 02:54


Quote: Originally posted by fusso  
Can piranha solution oxidize gold, Pt and other PGMs?


No, piranha solution is sometimes used for cleaning of gold or Pt plated stuff.




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[*] posted on 26-4-2019 at 03:23


Quote: Originally posted by bipolar  
Does acetonitrile react with sodium metal? If so, what are the products of this reaction?
I'm hoping this might be the way to make some sodium cyanide. :D


[Edited on 21-4-2019 by bipolar]


Seems like reducing acetonitrile yields acetic acid and ammonia, at least in ethanol.

Acetonitrile metabolizes in to cyanide, so all you need is volunteer as an one time reactor and a way to extract cyanide from dead body and you are good to go.




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