Sciencemadness Discussion Board - The Short Questions Thread (4)

Any thoughts on buying a decibel meter, what weaknesses or drawbacks come into play or best buy on eBay? There're some for 15 dollars or so supposedly very accurate.

If you've a half decent smartphone, look for any number of free apps which use your phone's hardware to act as a decibel meter.

Some of them seem to work pretty well.

Morgan - 5-12-2019 at 10:37

Thanks for those thoughts all. I was reading some of the complexities of measuring sound on Wiki. This was interesting too.

"However, the reading from a sound level meter does not correlate well to human-perceived loudness, which is better measured by a loudness meter. Specific loudness is a compressive nonlinearity and varies at certain levels and at certain frequencies.These metrics can also be calculated in a number of different ways."
https://en.wikipedia.org/wiki/Sound_level_meter

Sulaiman - 5-12-2019 at 19:27

Accoustics and auditory perception is a complex area,
accoustics and especially sonar were the key topics of some of my lecturers and their post-grad researchers,
about 30 years ago I was designing, building and selling (small private sales) 'Hi-Fi' equipment,
one of the important areas is perceived loudness
https://en.wikipedia.org/wiki/Equal-loudness_contour
but the most complex is Psychoacoustics
https://en.wikipedia.org/wiki/Psychoacoustics
(I can discuss this topic ad nauseum)

What is the intended use for the sound level meter ?

Morgan - 6-12-2019 at 10:56

I wanted to know the level of sound some of my smallish jam jar jets make with exhaust tubes attached which increases the robustness enough so that I wear hearing protection - just hot gases going in and out a single orifice somewhat fast.

This sort of thing as an example.
https://www.youtube.com/watch?v=T-EoSOfaplo

j_sum1 - 9-1-2020 at 01:32

Quote: Originally posted by j_sum1

My hardware store hydrochloric acid seems to be contaminated with Ti (of all things).
It gives a pale purple / lilac cloudy hue when reacting with zinc or magnesium.
It forms a bright orange complex with a very small of dilute peroxide.

Or is there something else that would give this same set of results?
How would titanium contamination even happen?

Bumping this since the exact same question with the same product has come up with another user. I think Ti is the most likely culprit: nothing else I know fits the symptoms. But how would Ti have gotten in there? Seems a mystery.

sodium bichloride (say what?)

j_sum1 - 9-1-2020 at 01:57

My latest project has been installing a small swimming pool. It is filling as I type. (Yay! Relief from the aussie heat!)
It comes with a couple of manuals that appear to have been kludged together from a range of models and passed through at least one poor translation process. It is a bit unclear to say the least.
When it comes to the section(s) on chemicals to maintain correct water chemistry, there is a mountain of conflicting and contradictory information. It mentions sodium dichloroisocyanuric acid. It also mentions bromine in one place. It has an ozone generator and so mentions that. It recommends monopersulfate. But the bulk of the instruction centres around "sodium bichloride". I am wondering what on earth is meant by that.

Any insights? It is clearly an inappropriate name for something. But what? Does anyone know of any pool chemicals that are commonly misnamed as sodium bichloride?

woelen - 9-1-2020 at 02:57

The only one I can think of is sodium hypochlorite. Where I live, we can buy big jugs (10 liters, or even 20 liters) of 12.5% active chlorine (solution of NaOCl in water). This is poured in a swimming pool for chlorinating purposes. Sometimes it is combined with cyanuric acid in order to stabilize the chlorine. This is important for outdoors swimming pools in full sunshine, which otherwise suffer from rapid decomposition of the hypochlorite to chloride and oxygen by UV-light.

karlos³ - 9-1-2020 at 04:38

Maybe they meant sodium bisulfate, which is a common pH-down pool chemical?

wg48temp9 - 9-1-2020 at 08:32

Quote: Originally posted by j_sum1

My latest project has been installing a small swimming pool. It is filling as I type. (Yay! Relief from the aussie heat!)
It comes with a couple of manuals that appear to have been kludged together from a range of models and passed through at least one poor translation process. It is a bit unclear to say the least.
When it comes to the section(s) on chemicals to maintain correct water chemistry, there is a mountain of conflicting and contradictory information. It mentions sodium dichloroisocyanuric acid. It also mentions bromine in one place. It has an ozone generator and so mentions that. It recommends monopersulfate. But the bulk of the instruction centres around "sodium bichloride". I am wondering what on earth is meant by that.

Any insights? It is clearly an inappropriate name for something. But what? Does anyone know of any pool chemicals that are commonly misnamed as sodium bichloride?

Perhaps if you gave more context by posting the relevant section of the instructions it may be obvious what chemical they are referring to.

If the instructions are unclear and conflicting why not ignore them. There is lots of info on the web about maintaining the chemistry of a swimming pool. I would think if you are going to use the ozone generator you will have to pick a chemistry that's compatible with that.

j_sum1 - 9-1-2020 at 14:12

Clearest statement anywhere in the manual:

Quote:

We recommend using chlorine particles of sodium bichloride for water disinfection, because sodium bichloride can be completely and rapidly dissolved in water and its PH value is close to neutral.

The most likely candidate would be Na-DCCA. Sodium salt with two chlorines so the name fits. Soluble solid with little affect on pH.

You are correct: I am not going to rely on the manual since it is so unclear. But it was important to read anyway. I do need to select a treatment process compatible with materials used in the pool. I have read a few online guides as well. I am happy with the chemical theory. I am not happy with some of the terminology and descriptions given. And I am trying to get my head around quantities. All the guides refer to "total alkalinity" measured in ppm as separate from pH. I would much prefer molar concentration of carbonate if that is what is meant. I have read some truly shocking descriptions of chemical equilibrium. Fortunately there is some good information amidst all the crap out there.

arkoma - 9-1-2020 at 14:37

The Mandarin to English translator strikes again

*edit* pulled some generic acetaminophen by refluxing the pills in acetone. The damn stuff xtallized this weird reddish color. Any thoughts?

[Edited on 1-9-2020 by arkoma]

CharlieA - 9-1-2020 at 18:46

Did you use pills that may have contained a red dye? Perhaps the dye was adsorbed on the crystals. You could try treating your acetone solution with activated carbon to remove the dye before the crystallization step. Also, washing the crystals on the filter with acetone may remove the dye, assuming that it is adsorbed onto the crystals of product.

yobbo II - 22-1-2020 at 16:12

Does anyone know where I can get a datasheet for a R450 photo multiplier tube.

TIA,
Yob

Abromination - 26-1-2020 at 11:07

Can sodium sulfate be used instead of potassium sulfate to precipitate neodymium and iron as a double sulfate salt?
Thanks

clearly_not_atara - 29-3-2020 at 11:49

A lot of sources say that phenylacetic acids are especially prone to decarboxylation. However, I've had trouble finding any published reports describing this decarboxylation under ordinary conditions. There are some papers about gas-phase decarboxylation, papers in supercritical water, papers using UV-C photodecarboxylation, etc. I've heard the vinylogy explanation but experimentals, kinetics etc are hard to find since you just get a bunch of recent papers using this or that catalyst for decarboxylative whatever.

In particular, the simple decarboxylation of naproxen to 2-methoxy-6-ethylnaphthalene is widely reported as an undesired side-reaction, but if you search for references you get a bunch of catalytic oxidative decarboxylations which give the wrong product and are overcomplicated. I did find this:

https://pubs.acs.org/doi/10.1021/jp805614y

although at this point it might be faster to just CWE some Aleve and leave it out in the sun to see what happens

Abromination: this double salt is called "eldfellite", the data page describes it as "water-sensitive". i don't know a damn thing about neodymium. however, sodium generally does not do as good a job as potassium when it comes to precipitating highly symmetric anions like ClO4-, IO4-, or in this case Fe(SO4)2-. I don't know a damn thing about neodymium, unfortunately.

https://www.mindat.org/min-35791.html

[Edited on 29-3-2020 by clearly_not_atara]

Tsjerk - 1-4-2020 at 07:56

I found some 2,2-bipyridine! Some ideas to do some nice coordination chemistry with it?

clearly_not_atara - 1-4-2020 at 14:32

It forms lots of copper complexes, which are apparently good Ullmann reaction catalysts and can also catalyze the dehydrogenation of alcohols with atmospheric oxygen.

clearly_not_atara - 12-4-2020 at 10:18

Does the Sandmeyer reaction work for alkyl fluorides with alkali nitrite and hydrofluoric acid? All I can find with Google are a bunch of sites mentioning that it doesn't work well for aryl fluorides, but copper is not required for the alkyl Sandmeyer reaction, so that doesn't tell me very much.

Lion850 - 13-4-2020 at 02:42

I tried to process lead-tin solder into iodides. The lead went well, but the tin nearly all ended up as a very fine white powder which I assume is tin (iv) oxide SnO2. This powder seems very unreactive. It did not dissolve in room temperature HCl. With very hot H2SO4 I got a charcoal coloured substance which seems inert. Any suggestions how SnO2 can be processed into other tin salts?

mackolol - 20-4-2020 at 01:29

Hey, I have short question. Is it better (for glass or in general) to apply vacuum to distillation setup when it is fully heated, or to apply it at the beginning and then heat along with vacuum?

[Edited on 20-4-2020 by mackolol]

Sulaiman - 20-4-2020 at 03:45

Apply vacuum first then heat,
if you heat first, when you apply vacuum there is a good chance of violent boiling.

fusso - 20-4-2020 at 03:56

Apply vacuum first then heat,
if you heat first, when you apply vacuum there is a good chance of violent boiling.

You forgot that the heat would also increase the pressure causing an explosion.

mackolol - 20-4-2020 at 08:28

Apply vacuum first then heat,
if you heat first, when you apply vacuum there is a good chance of violent boiling.

But is there any other disadvantage beside too violent boiling? (maybe glassware damage)

Quote: Originally posted by fusso

You forgot that the heat would also increase the pressure causing an explosion.

Ah, right

Has anyone checked the 'accuracy' of cheap Chinese pH papers ?

Sulaiman - 25-4-2020 at 04:20

mackolol - 25-4-2020 at 05:36

I'm using ones and they work quite well for my purposes, but the scale isn't very precise..

karlos³ - 30-5-2020 at 23:33

The chemoluminescence reaction with NaBH4 and KMnO4 is known I would guess?
I would like to try it soon, but the reaction also calls for sodium hexametaphosphate which I don't have.

But why is that stuff involved?
I don't understand it, because actually, it is not really involved:
NaBH4 + Mn(III, IV or VIII)/H+→ products + Mn(II)*→ Mn(II) + light (~690nm)

What does this salt do in there? Is it needed?
Can it be replaced, if so, what can I use as replacement?
I read up on that, and besides it seems that it can be substituted with sodium orthophosphate, and that it is only in there because it affects the wavelength.

What would be a good replacement? I have no phosphorus acid, neither its salts.
chemplayer uses phosphoric acid, instead of the sulfuric, is it just for acidification used, or does it affect the wavelenght as well?
Only P-containing substance I can offer would be some sodium hypophosphite.

Can someone help? I would really love to try it, but I'm just not sure if it is even worthwhile under these circumstances.

wg48temp9 - 31-5-2020 at 08:58

Quote: Originally posted by karlos³

The chemoluminescence reaction with NaBH4 and KMnO4 is known I would guess?
I would like to try it soon, but the reaction also calls for sodium hexametaphosphate which I don't have.

But why is that stuff involved?
I don't understand it, because actually, it is not really involved:
NaBH4 + Mn(III, IV or VIII)/H+→ products + Mn(II)*→ Mn(II) + light (~690nm)

What does this salt do in there? Is it needed?
Can it be replaced, if so, what can I use as replacement?
I read up on that, and besides it seems that it can be substituted with sodium orthophosphate, and that it is only in there because it affects the wavelength.

What would be a good replacement? I have no phosphorus acid, neither its salts.
chemplayer uses phosphoric acid, instead of the sulfuric, is it just for acidification used, or does it affect the wavelenght as well?
Only P-containing substance I can offer would be some sodium hypophosphite.

Can someone help? I would really love to try it, but I'm just not sure if it is even worthwhile under these circumstances.

You should read the following paper:
Attachment: Mechanism-Permanganate-Chemiluminescence-hindson2010.pdf (436kB)
This file has been downloaded 469 times

Apparently polyphosphate ions complex Mn3+ which increases the chemoluminescence 50 fold. The correct ph is also required.

Interestingly phenols and ascorbic acid can be used in place of the NaBH4.

mayko - 31-5-2020 at 11:53

You might be interested in this too (same first author)

Hindson, C. M., Smith, Z. M., Barnett, N. W., Hanson, G. R., Lim, K. F., & Francis, P. S. (2013). Autocatalytic Chemiluminescence Sheds New Light on the Classic Permanganate–Oxalate Reaction. The Journal of Physical Chemistry A, 117(19), 3918–3924. https://doi.org/10.1021/jp312603m

Attachment: Hindson et al. - 2013 - Autocatalytic chemiluminescence sheds new light on the classic permanganate-oxalate reaction.pdf (1.6MB)
This file has been downloaded 484 times

karlos³ - 31-5-2020 at 17:26

Thank you both very much!

karlos³ - 18-6-2020 at 06:06

I need some dimethylamine freebase, and I have DMF, can I hydrolyse it with base simply at RT?0
That would be very practical for me, giving me a solution I can use directly as it is for the reductive amination I intend to use it for.
If not, I guess I have to go via the HCl hydrolysis instead.

stoichiometric_steve - 18-6-2020 at 12:24

Quote: Originally posted by karlos³

I need some dimethylamine freebase, and I have DMF, can I hydrolyse it with base simply at RT?0
That would be very practical for me, giving me a solution I can use directly as it is for the reductive amination I intend to use it for.
If not, I guess I have to go via the HCl hydrolysis instead.

Why not hydrolyze with NaOH with heating, driving off the Dimethylamine through a drying column and collecting it in chilled MeOH until saturated?

karlos³ - 18-6-2020 at 12:37

Because the smell lingers

Well guess I rather go via the HCl hydrolysis.
Its better and easier stored this way.
My ketone is a hydroxyketone as you well know, and so it will form an imine very readily and a stable one even.

stoichiometric_steve - 26-6-2020 at 15:37

Quote: Originally posted by karlos³

Because the smell lingers

Well guess I rather go via the HCl hydrolysis.
Its better and easier stored this way.
My ketone is a hydroxyketone as you well know, and so it will form an imine very readily and a stable one even.

You have a point there, but i think a solution in MeOH would be way more versatile, and if set up correctly, you won't even have to deal with any fumes whatsoever.

Belowzero - 3-7-2020 at 04:48

After the whole corona thing dies down I expect the market to be flooded by used cheap plexiglass , perhaps even free.
While looking for fumehood designs I stumbled across designs that are made entirely out of plexiglass , although not the most important feat. it looks really slick.
Relatively easy material to work with and not too heavy.

Now I wonder if this material is resistant enough to withstand at least a few years of abuse?
I could coat the parts exposed to the highest airflow volume with say epoxy/paint to make it more resilliant.

[Edited on 3-7-2020 by Belowzero]

Σldritch - 5-7-2020 at 12:24

How much space do i need for GAMESS, macmolplt and avogadro? I want to look at orbitals of up to maybe 30 atom clusters and only have 30Gb. Do i even have enough space for all the programs?

karlos³ - 30-7-2020 at 14:40

How reliable is this patent regarding the reductive amination of napthylglyoxyl hydrate?
Can aldehyde hydrates be reductively aminated like this? Never saw another example of it so far.
The patent is United States Patent Office 3,463,808, like look at example 13.
Or, United States Patent Office 3,312,733, example 9.
What do you guys think? I'm trying to run a reductive amination of 2-naphthylglyoxyl hydrate right now, but I am not so confident it will work.
Still in the process of aldimine formation.

karlos³ - 31-7-2020 at 11:51

Sadly, it didn't seem to work so far.
I still have to work it up properly, but after an acidic quench way too much oil fell out, indicating my substrate hasn't reacted to an amine as intended.

Can someone shoot an opinion about these doubtful patents please?

LuckyWinner - 8-8-2020 at 01:25

i dried my calcium chloride dehydrate inside an old iron pan with some minor rust on the stove.

my CaCl appears dry but it now has a slight reddish , (iron oxide?) tint.

will this cause any trouble when drying diethyl ether for example or other solvents?

how can I clean my CaCl from the rust contamination?

Sulaiman - 20-8-2020 at 03:07

I want to make chloroform via the haloform reaction but I am presently unable to cool the bleach so
can I add acetone to RT bleach a little at a time over an extended period?
E. G. 5L 6% sodium hypochlorite plus acetone in 10ml portions over several hours to allow cooling.
and
acetone bp=56C, how high can I allow the temperature of the mixture to get without significant losses?

j_sum1 - 20-8-2020 at 04:38

I want to make chloroform via the haloform reaction but I am presently unable to cool the bleach so
can I add acetone to RT bleach a little at a time over an extended period?
E. G. 5L 6% sodium hypochlorite plus acetone in 10ml portions over several hours to allow cooling.
and
acetone bp=56C, how high can I allow the temperature of the mixture to get without significant losses?

No expert. I have only done it a few times.
I have always heard that you need to keep temp brlow 20C during the reaction and that NaOH byproduct causes chloroform to decompose. Both of these would suggest problems with what you propose.
Can't you buy a bag of ice?

S.C. Wack - 20-8-2020 at 13:58

The only time anyone does it (edit: should do it) cold is when they are trying to do it without glassware.

[Edited on 21-8-2020 by S.C. Wack]

Sulaiman - 20-8-2020 at 21:31

I tried 5L of 5.5% NaOCl with 200ml acetone at RT (c30^oC)
here is a view of the crude product :
yield.jpg - 30kB

A yield of 3.7%

____________________________________________________
I am fairly confident that the bulk of the remaining available chloroform (estimate >60ml) is dissolved in the 5L of water.
I may try distilling the 5L solution sometime later to see what I can recover.
_____________________________________________________
Judging by smell (which is not quantitive) there was significant evaporation of chloroform during the experiment.
... 200ml of chloroform lost to the 5L solution and the environment

______________________________________________________

Do not waste effort trying this at home

===============================================
next: playing with tcca per this thread and links http://www.sciencemadness.org/talk/viewthread.php?tid=5686

Jimmymajesty - 1-9-2020 at 13:14

Is there an easy way to convert N'N'diethyl hydroxylamine back to hydroxylamine? Thanks for your help!

solo - 8-9-2020 at 09:04

What is this piece used for....some type of trap .?......solo

5E578C39-EA28-4B4D-946F-BE9D527C218D.jpeg - 1.8MB

RogueRose - 8-9-2020 at 15:57

I tried 5L of 5.5% NaOCl with 200ml acetone at RT (c30^oC)
here is a view of the crude product :

A yield of 3.7%

______________________________________________________

Do not waste effort trying this at home

===============================================
next: playing with tcca per this thread and links http://www.sciencemadness.org/talk/viewthread.php?tid=5686

Was your bleach new? I've heard of low yields from using old NaOCl. Did you chill the bleach and the acetone before mixing the two?

RogueRose - 8-9-2020 at 16:02

Well you kind of cut off the bottom of the picture, is it just sealed glass at the bottom? Also, does the tube from the top & middle section seal to the bottom tube, or is it open at the bottom?

solo - 8-9-2020 at 17:16

sealed at the bottom with a small hole on the upper side...and open on top ....solo

[Edited on 9-9-2020 by solo]

[Edited on 9-9-2020 by solo]

CharlieA - 9-9-2020 at 17:03

Just a WAG (as opposed to a SWAG): could this be some kind of device to deliver 10 mL of a reagent from some kind of reservoir?

B(a)P - 11-9-2020 at 02:34

Some time ago I purchased a cheap condenser and it came with an addition funnel. I used the addition funnel for the first time today and it was almost impossible to get a constant drip rate. Can I replace the tap to get something usable, any tips for getting crappy taps to perform or do I just forget it?

clearly_not_atara - 11-9-2020 at 04:39

Quote: Originally posted by S.C. Wack

The only time anyone does it (edit: should do it) cold is when they are trying to do it without glassware.

For the reaction this is true, but in order to achieve the best phase separation at workup you want the solution to be just barely above freezing IIRC

paulll - 12-9-2020 at 19:53

Has anybody ever heard of such a thing as a spring-loaded flask clamp? With how handy it would be for receiving flasks it seems to be a thing that should exist and yet I don't see any anywhere.

karlos³ - 12-9-2020 at 22:42

Quote: Originally posted by paulll

Has anybody ever heard of such a thing as a spring-loaded flask clamp? With how handy it would be for receiving flasks it seems to be a thing that should exist and yet I don't see any anywhere.

Could you draw one, just a bad sketch to get the idea?
I'm not sure how that should look like.

I hope not like that: https://www.sigmaaldrich.com/content/dam/sigma-aldrich/produ...
Because that would mean they stole and produced your idea, and that in merely hours!
Those capitalist pigs, no respect on your intellectual property!

But seriously, like that?
Because initially I imagined a clamp to hold the receiving flask connected with the vacuum adapter(or cow) or such.
Just a plain flask clamp.
Only that I can't picture how such a thing would look like spring-loaded, which is why I was asking for a sketch of it.
And promised, not to steal the idea and sell it to sigma or whoever bids most, you have my hobby chemist word of honor on that!

paulll - 13-9-2020 at 18:26

Notwithstanding the fact that I can't draw with or without a computer... something like this. I'm thinking, e.g., for the receiving flask in a distillation rig - or any other flask that you'd want to change out mid-experiment.
So instead of tightening a thumbscrew to apply pressure to the piece, you'd be unscrewing it to release spring tension onto it, to hold it in place. The flask could then be removed and replaced by squeezing the other end of the clamp scissors-style. If that makes sense lol

Untitled 1.png - 12kB

[Edited on 14-9-2020 by paulll]

Morgan - 29-9-2020 at 07:54

Does anyone know a company that makes these cylindrical volumetric flasks?

https://i.ebayimg.com/images/g/QqkAAOSwg35atCrz/s-l1600.jpg
https://i.ebayimg.com/images/g/GLsAAOSwuHZatCr0/s-l1600.jpg

Antigua - 29-9-2020 at 08:02

Does anyone know a company that makes these cylindrical volumetric flasks?

https://i.ebayimg.com/images/g/QqkAAOSwg35atCrz/s-l1600.jpg
https://i.ebayimg.com/images/g/GLsAAOSwuHZatCr0/s-l1600.jpg

https://www.wilmad-labglass.com/
Here - I found them through a simple search, but they do look very expensive.

[Edited on 29-9-2020 by Antigua]

Morgan - 29-9-2020 at 15:22

Quote: Originally posted by Antigua

Does anyone know a company that makes these cylindrical volumetric flasks?

https://i.ebayimg.com/images/g/QqkAAOSwg35atCrz/s-l1600.jpg
https://i.ebayimg.com/images/g/GLsAAOSwuHZatCr0/s-l1600.jpg

https://www.wilmad-labglass.com/
Here - I found them through a simple search, but they do look very expensive.

[Edited on 29-9-2020 by Antigua]

I see some cylindrical volumetric flasks there but not the identical shape. There are also square volumetric flasks I found that are close to it in proportion such as this one.
https://www.gogenlab.com/lab-supplies/flasks/volumetric-flas...
Just now found it.
https://kinesis.co.uk/dissolution-900ml-volumetric-flask-wit...

Morgan - 2-10-2020 at 07:01

Quote: Originally posted by Antigua

Does anyone know a company that makes these cylindrical volumetric flasks?

https://i.ebayimg.com/images/g/QqkAAOSwg35atCrz/s-l1600.jpg
https://i.ebayimg.com/images/g/GLsAAOSwuHZatCr0/s-l1600.jpg

https://www.wilmad-labglass.com/
Here - I found them through a simple search, but they do look very expensive.

[Edited on 29-9-2020 by Antigua]

I noticed this 2 liter size is listed for $210.89 and probably shipping costs. I decided to buy that shape having found 4 of them (same Kimble 28040 flask) for sale for $34.25 each or best offer on eBay, new old stock so I bought one along with free shipping. The square flask is 5 X 5 X 18 inches.
https://www.gogenlab.com/lab-supplies/flasks/volumetric-flas...

[Edited on 2-10-2020 by Morgan]

j_sum1 - 18-10-2020 at 16:56

Anyone able to give any enlightenment as to what this reaction is?
https://www.youtube.com/watch?v=cVxySCgUy8A

I thought it was a stunning demo and one I would love to add to my repertoire.
CoCl2 I have. But what is the reaction mixture being used? And what kind of complexing causes the green?

DraconicAcid - 18-10-2020 at 17:19

Quote: Originally posted by j_sum1

Anyone able to give any enlightenment as to what this reaction is?
https://www.youtube.com/watch?v=cVxySCgUy8A

I thought it was a stunning demo and one I would love to add to my repertoire.
CoCl2 I have. But what is the reaction mixture being used? And what kind of complexing causes the green?

Might be basic peroxide and carbonate? Or basic peroxide and oxalate?

B(a)P - 18-10-2020 at 19:02

https://uwaterloo.ca/chem13-news-magazine/march-2014/activities/sharing-chemistry-community-colorful-catalyst

I think this is what you are after.

j_sum1 - 18-10-2020 at 19:23

Quote: Originally posted by B(a)P

https://uwaterloo.ca/chem13-news-magazine/march-2014/activities/sharing-chemistry-community-colorful-catalyst

I think this is what you are after.

Awesome. that is just great!

SHADYCHASE54 - 6-11-2020 at 07:16

Hello I have a quick question regarding how to convert aniline back to actilanilide? I assum it's simple base hydrolysis? Does anyone know of a decent procedure? I have used TFSE and am coming up with nada. I would rather start from a known procedure then go the route of trail and error as I only have a small amount of the previously stated starting material; as such I would like to optimize the yield.

Antigua - 6-11-2020 at 07:31

Quote: Originally posted by SHADYCHASE54

Hello I have a quick question regarding how to convert aniline back to actilanilide? I assum it's simple base hydrolysis? Does anyone know of a decent procedure? I have used TFSE and am coming up with nada. I would rather start from a known procedure then go the route of trail and error as I only have a small amount of the previously stated starting material; as such I would like to optimize the yield.

Why would it be a base hydrolysis? You have to acetylate the amine, for example using glacial acetic acid and zinc dust.

SHADYCHASE54 - 6-11-2020 at 10:49

I want to convert the acetanilide back to the amine. My desired product is aniline made by reacting acetanilide, I think with a base, to convert it into aniline. Can anyone help me with this?

Thank you in advance for any help you may provide.

Antigua - 6-11-2020 at 11:00

Quote: Originally posted by SHADYCHASE54

I want to convert the acetanilide back to the amine. My desired product is aniline made by reacting acetanilide, I think with a base, to convert it into aniline. Can anyone help me with this?

Thank you in advance for any help you may provide.

Now it makes more sense! In your original question you mentioned the other reaction, making acetanilide out of aniline.
Anyways, here are some sources you might find useful:
1. Hydrolysis of acetanilide, attached
2. Reactivity of Acetanilides in the Alkaline Hydrolysis Reaction: Theory vs. Experiment, attached

Attachment: article.pdf (522kB)
This file has been downloaded 893 times

Attachment: Reactivity_of_Acetanilides_in_the_Alkaline_Hydroly.pdf (533kB)
This file has been downloaded 346 times

SHADYCHASE54 - 6-11-2020 at 19:35

Thanks Antigua, sorry if you found my first post unclear, regardless thanks for the reaction information you rock.

Be well.

Johnny Cappone - 22-12-2020 at 04:21

Hi, guys!
I have some questions that I don't think are worthy of a topic of their own. These are as follows:

1) Is it possible to concentrate a diluted solution of nitric acid (say, 10%) to its azeotrope (68%) simply by heating it, as is done with sulphuric acid?

2) When I distill concentrated sulfuric acid (98%) and KNO3, do I get fuming nitric acid that boils at 83-6 degrees or the azeotrope?

3) If, on the other hand, I use diluted sulfuric acid (30%) in the previous operation, will I get 30% HNO3 or the azeotrope?

Thanks!

Antigua - 22-12-2020 at 04:46

1. Yes
2. Fuming
3. You'd get a solution of HNO3 (less than 68%) that can be distilled fractionally or simply to get the azeotrope.

Tsjerk - 22-12-2020 at 05:20

1) Is it possible to concentrate a diluted solution of nitric acid (say, 10%) to its azeotrope (68%) simply by heating it, as is done with sulphuric acid?

2) When I distill concentrated sulfuric acid (98%) and KNO3, do I get fuming nitric acid that boils at 83-6 degrees or the azeotrope?

3) If, on the other hand, I use diluted sulfuric acid (30%) in the previous operation, will I get 30% HNO3 or the azeotrope?

Thanks!

1) In a perfect world you would boil of the water at 100 degrees, until the nitric acid reaches 68%, which would then come over at 120 degrees. In reality, depending on the efficiency of your fractionation, you will start with acid coming over a little bit over 100 degrees, slowly rising in concentration until it reaches almost 120 degrees.

The efficiency of your fractionation depends mostly on the length of your column and the speed at which you distill the acid.

2) The acid you collect from KNO3 and H2SO4 will be nearly anhydrous, but will contain a lot of NO2. I think adding water to the KNO3/H2SO4 to get azeotropic acid works better in terms of NO2 produced. You can later make anhydrous acid by adding H2SO4 to the 68% HNO3, preferably distilled under vacuum.

3) The HNO3 collected from 30% H2SO4 will behave like the acid in procedure 1. You will first collect less concentrated HNO3, followed by acid closer to the azeotrope.

[Edited on 22-12-2020 by Tsjerk]

artemov - 24-12-2020 at 08:00

Just want to do a quick check if isopropanol salted-out with NaCl from 70% is safe to distill?

Antigua - 24-12-2020 at 08:04

Why not? Alcohols don't form peroxides like ethers.

teodor - 24-12-2020 at 09:16

1) Is it possible to concentrate a diluted solution of nitric acid (say, 10%) to its azeotrope (68%) simply by heating it, as is done with sulphuric acid?

The problem is very slope concentration/boiling temperature curve, so it is like most of the acid (4/5 when you start with 50%) goes before azeotrope. The fraction 119-121 degree will contain 50-55% and only when you get the first signs of NO2 inside the condenser you can collect something around 63-68%.
I think addition of sulfuric acid could help, on rough estimation it keeps 20-30% of water by weight of H2SO4 so it will look like you will starting with more concentrated acid vapours.

2) When I distill concentrated sulfuric acid (98%) and KNO3, do I get fuming nitric acid that boils at 83-6 degrees or the azeotrope?

When NOx is present the boiling point goes down to 80-81%. You can get either red fuming or white fuming nitric acid but the latest one I believe you can get starting only with azeotrope of high purity (without vacuum). There is a lot of difference between 97.5% and 100% HNO3 (in oxidation power) and if you don't need it as a rocket oxidiser I suggest get it around 98%. This usually will be result when the equipment, the bottle and the air is not perfectly dry.