Sciencemadness Discussion Board - The short questions thread (3)

The short questions thread (3)

Pages: 1 2 3 4 .. 8

arsphenamine - 13-10-2010 at 07:50

n.b. the c=c bond is c2-c3

The trivial name for the aliphatic homolog is 2-methyl 3-phenyl propionaldehyde.

Pope - 16-10-2010 at 23:16

Quote: Originally posted by Sedit

Quote: Originally posted by Pope

How would one approach trying to separate an azeotropic mixture of Toluene/Methyl Ethyl Ketone, my goal is to completely separate and purify the existing Toluene.

The components exist as - 430g Toluene: 410g MEK.

Thank you for your assistance, I have tried the search engine with little success.

Sodium Metabisulfite will form a complex precipitating the MEK as an adduct. Repeated washes of the MeBn with Bisulfite solution should clear up your problem.

In order to run this reaction wouldn't you use ethanol to dilute the solution in turn forming another azeotrope with the toluene?

Random - 21-10-2010 at 01:10

I have few questions:

1. I have nail polish remover that has MEK, water, isopropyl alcohol, methoxyisopropanol, calcium chloride. I want to precipitate MEK with potassium metabisulfite. After that, how can I extract MEK from that extract without distillation?

2. Can I stabilize chloroform with brandy?

3. Is there some use for Copper (II) acetate in organic chemistry?

4. How could I extract chromium from stainless steel?

Thanks for answers

bbartlog - 21-10-2010 at 14:57

1) No idea.
2) Should work, add brandy, some ethanol will go in to the chloroform phase, then separate the aqueous phase. But your chloroform will be wet and also likely contaminated with miscellaneous crap from the brandy that prefers to be in a non-polar solvent; why not distill the brandy first to get something closer to pure ethanol?
3) Yes
4) There is a thread on this here somewhere... see http://www.sciencemadness.org/talk/viewthread.php?tid=13347#...

not_important - 21-10-2010 at 15:40

The bisulfite-MEK adduct is fairly water soluble, even with a saturated solution of bisulfite some of the adduct remains in solution. Given the CaCl2 in it, best to first distill and collect the portion boiling at or below 80 C, then make the addition product.

2-butanone.png - 242kB

Sedit - 21-10-2010 at 15:55

Quote: Originally posted by Pope

In order to run this reaction wouldn't you use ethanol to dilute the solution in turn forming another azeotrope with the toluene?

No need for ethanol since you don't wish to precipitate the adduct just wash it with Bisulfite solution.

Pope - 21-10-2010 at 21:18

Quote: Originally posted by Sedit

Quote: Originally posted by Pope

In order to run this reaction wouldn't you use ethanol to dilute the solution in turn forming another azeotrope with the toluene?

No need for ethanol since you don't wish to precipitate the adduct just wash it with Bisulfite solution.

And the resulting adduct will dissolve in the bisulfite solution?

Sedit - 23-10-2010 at 16:44

Does anyone know if AcOH would react with CaCl2?

Im pretty sure it doesn't but before I use it as a drying agent to report the yeilds on my Dichloromethane extraction of acetic acid I want to be 100% sure it won't give me issues. I would normally use MgSO4 for this but I am all out and forgot to pick some up.

Acetic acid was made from Sodium acetate and Sodium Bisulfite and the addition of DCM showed a small H2O layer on the top that I want to do away with before filtering since it will hold more AcOH then I want it to decreasing yeilds.

not_important - 23-10-2010 at 17:06

Most CaCl2 contains some Ca(OH)2 and/or CaCO3, which obviously don't go with AcOH. Also CaCl2 forms adducts with compounds containing -OH, -NR2 (especially -NH2), and C=O; while not strictly a reaction and of less strength than the CaCL2-H2O adduct, they will get pulled from solutions to some extent. Strong aqueous CaCll2 solutions will be less absorbent of those compounds, still Na2SO4 or MgSO4 would be a better choice.

Sedit - 23-10-2010 at 21:13

The desired goal is to use anhydrous CaCl2 and add just a small amount to dry DCM/GAA mixture. Without very much H2O present (and non when its done its job)do you feel it will still have this problem?

DeAdFX - 25-10-2010 at 12:31

I did some research on protecting graphite anodes in a chlorate cell. Coating the anode with polystyrene, linseed oil or some other material will result in a more durable anode.

I decided to coat my anode in polystyrene. After doing so my anode is bubbling much less in comparison. Is less bubbling indicative of a more durable anode? Did I apply too much and has my efficiency gone down?

bbartlog - 25-10-2010 at 14:01

Seems like you will want to measure current flow to have an idea of what is going on. It seems *likely* that you coated it too thickly and that the polystyrene has formed an electrically resistant layer, but measuring the amps would give you a clearer picture of what's going on.

Sedit - 27-10-2010 at 15:53

I tryed extracting AcOH using acetone but I fear excess Sulfuric acid left over in the Acetic acid synthesis has led to an aldol condensation product of somekind.

It smells like cat piss or some other foul smell and appears to be dark brown in color but this could be impurities in the sulfuric acid used.

solo - 27-10-2010 at 16:23

Uploaded with ImageShack.us

...trying to name this compound....some help....solo

not_important - 27-10-2010 at 17:38

3-phenyl-2-methyl-propanoal (or propionaldehyde) oxamine is what I would call it, at first look. Likely someone who keeps up on terminology will correct that, so I get to learn something.

solo - 28-10-2010 at 07:02

Quote: Originally posted by not_important

3-phenyl-2-methyl-propanoal (or propionaldehyde) oxamine is what I would call it, at first look. Likely someone who keeps up on terminology will correct that, so I get to learn something.

....thanks, you gave a good educated name, here is the name of the material.......2-methyl-3-phenylpropanal it's not the oxime but that will be easier to find......with the main skeleton name

Uploaded with ImageShack.us

......source,

http://www.chemsynthesis.com/base/chemical-structure-6195.ht...

[Edited on 28-10-2010 by solo]

[Edited on 28-10-2010 by solo]

not_important - 28-10-2010 at 09:49

Yeah, forgot the rule that numbers goes from low to high, payed too much attention to the mass of the radical. Duh ... Old age is taking its toll.

solo - 28-10-2010 at 13:09

....has there been any reports of recimization when doing reductions of halogens with compounds with chiral centers , case and point and iodated phenylalaninol HCl.....based on a reading with a refractometer the index points to a recemic amine......solo

Random - 4-11-2010 at 15:42

what i would get if i would mix poor man's aqua regia (hcl + nh4no3) and benzoic acid? COuld I get some useful product out of this and I read somewhere that aromatic compounds give chloropicrin with aqua regia, is this true?

I would also like to make p-aminobenoic acid without nitration of benzoic acid (i don't have any sulfuric acid). Is there another route to it from benzoic acid?

[Edited on 4-11-2010 by Random]

not_important - 4-11-2010 at 16:49

Benzoic acid is a bad starting point for p- and o- substitution, meaning it's just about worthless for making PABA. There is a recent thread on making PABA, within the last week or so; read it and then ask further.

Bolt - 5-11-2010 at 00:19

Hi, I'm wondering whether anyone can point me toward a good review or book chapter describing elemental calcium as a reducing regent in organic synthesis.

DeAdFX - 7-11-2010 at 16:03

I plan on making some copper nitrate via double displacement of a nitrate salt and copper sulfate.

Which nitrate salt will produce the easiest to filter sulfate percipitate? Strontium or Barium?

solo - 8-11-2010 at 10:34

I have Nickel acetate and need Nickel chloride....is there a way to convert it to the chloride salt ....have looked in google and found nothing....will most likely be found in some inorganic text...will keep looking, but if someone knows i would appreciate the assist.....solo

Sedit - 8-11-2010 at 16:17

I would think roasting the acetate would leave you with the oxide which HCl would convert to the chloride but this is just an assumption with little thought put into it to be honest.

I have a question. I got a paint thinner that contains acetone,DCM,MeOH,Toluene and KOH.

I can not seem to seperate the layers very well using water and distillation bumps so bad even with boiling chips. Any suggestions on whats going on here. Im shocked DCM and KOH can even be in the same solution since my instincts tell me it would be a bad idea but I guess it can.

I only want the toluene and DCM so perhaps steaming it would be my best option I guess. Right now its my cheepest over the counter source of Toluene.

arsphenamine - 8-11-2010 at 21:00

Quote: Originally posted by solo

Uploaded with ImageShack.us

...trying to name this compound....some help....solo

N-(2-methyl-3-phenylpropylidene)hydroxylamine

To search PubChem or ChemSpider, try the SMILES string first.
The InChI string may be overkill. I'm guessing that stereochemistry isn't too important here.

SMILES: CC(CC1=CC=CC=C1)C=NO
InChI=1S/C10H13NO/c1-9(8-11-12)7-10-5-3-2-4-6-10/h2-6,8-9,12H,7H2,1H3

ACD/Labs has a freeware name generator that is limited to 50 atoms per compound including H. The commercial lite version is ~$150 and is
quite good. IUPAC, the nomenclature org, gives it their blessing.

ChemAxon's MarvinSketch is almost freeware, has an academic license hook, but handles larger structures. Not as slick as ACD/Name, but v. useful in other ways as well.

[Edited on 9-11-2010 by arsphenamine]

12AX7 - 8-11-2010 at 22:17

Quote: Originally posted by Sedit

I have a question. I got a paint thinner that contains acetone,DCM,MeOH,Toluene and KOH.

I can not seem to seperate the layers very well using water and distillation bumps so bad even with boiling chips. Any suggestions on whats going on here. Im shocked DCM and KOH can even be in the same solution since my instincts tell me it would be a bad idea but I guess it can.

I only want the toluene and DCM so perhaps steaming it would be my best option I guess. Right now its my cheepest over the counter source of Toluene.

Well geez, that sounds like an awful mix... like it could peel the paint right off your walls!....oh...

Hmm, acetone shouldn't be stable with KOH. It should undergo aldol condensation to mixed products (= black tar).

The acetone (if that's what it is) and MeOH are probably keeping everything miscible. I wonder if a sufficient quantity of H2O would break it into a "salted out" KOH+H2O layer, also containing most of the MeOH and acetone, with a DCM+toluene layer adjecent (above or below, depending on the ratio of the two, and how "salty" the water gets). If the densities are too similar, they won't seperate very well, and surfactants will prevent coalescence. I offer no guarantees...

Other than that, KOH could at least be neutralized with, say, H2SO4, precipitating insoluble K2SO4, without adding much water to the mix (HCl would work, forming KCl, but commercial HCl acid comes with a lot of water). You could then try distilling it again: maybe removing the salt will prevent it from bumping so much.

MeOH could be absorbed in CaCl2. This also works for H2O and EtOH. I don't know about acetone. If there's a lot of water present already that you didn't mention, this might not be as practical.

Tim

solo - 9-11-2010 at 12:20

Quote: Originally posted by solo

I have Nickel acetate and need Nickel chloride....is there a way to convert it to the chloride salt ....have looked in google and found nothing....will most likely be found in some inorganic text...will keep looking, but if someone knows i would appreciate the assist.....solo

.....not sure how to convert nickel acetate to the desired chloride, any more suggestions.....solo

not_important - 9-11-2010 at 12:31

Do you actually need the chloride? If so, ppt the basic carbonate, wash well, dissolve in HCL. A wasteful but simple way is repeated evaporation with hydrochloric acid. Do it in a distilling rig without taking to the point of crystal formation, capture the AcOH-HCl-H2O mix that comes over; NiCl in hydrochloric acid in the still pot.

solo - 11-11-2010 at 16:48

.......thanks , need it as a catalyst for an oxidation reaction .......nickel acetate won't work.....solo

mewrox99 - 20-11-2010 at 16:54

I have a quick question about pH, pOH and H3O+ concentration. Am I doing this right

Say I have a solution of HCl with an H3O+ concentration of 0.1mol-L

To work out it's OH- concentration I would do -log[0.1] to get a pH of 1

And go 14-1 to get a pOH of 13. OH- = 1.00*10^-pOH

So my OH- concentration is 1.00*10^-13

Random - 22-11-2010 at 10:21

Can I reduce ketones, carboxylic acids or aldehydes with iodine (HI) and red phosphorus?

12AX7 - 22-11-2010 at 15:39

Specifically, it's not 14, but the pKa of water, which is 14.something.

If you don't mind being off by a fractional amount, then 14 is close enough. Just don't write the result as 1.00 x 10^-13, because that is not the number's accuracy.

Tim

not_important - 22-11-2010 at 16:00

Quote: Originally posted by Random

Can I reduce ketones, carboxylic acids or aldehydes with iodine (HI) and red phosphorus?

Yes, no, yes. How far do you want to reduce them? HI can take C=O to CH2, plenty of other reducing methods will take C=O to HCOH

Nicodem - 23-11-2010 at 12:20

If they are not enolizable.

DJF90 - 23-11-2010 at 12:36

Quote: Originally posted by 12AX7

Specifically, it's not 14, but the pKa of water, which is 14.something.

If you don't mind being off by a fractional amount, then 14 is close enough. Just don't write the result as 1.00 x 10^-13, because that is not the number's accuracy.

Tim

I thought the pKa of water was 15.7...?

Sedit - 23-11-2010 at 12:47

Quote: Originally posted by 12AX7

Quote: Originally posted by Sedit

Well geez, that sounds like an awful mix... like it could peel the paint right off your walls!....oh...

I did a simple distillation of the mixture and the ratio of componates are in order, MeOH, Acetone, DCM, Toluene, KOH. So there is little KOH in the mix and it does not appear to be affecting verymuch at all. I did get some interesting results as for the first time ever after adding water(to make it fluid and distill better) and distilling I got a quadphasic mixture*(is that even a word)

Question: what sort of azeotrops am I looking at here and is toluene and DCM able to mix with each other?

Im pretty sure I have managed to seperate them pretty well but I was shocked to smell the remains of the flask one time and smell what I am almost positive was the smell of benzaldahyde.

Magic Muzzlet - 24-11-2010 at 10:36

I have a question about a result of methoxylation of bromovanillin. After a day of boredom I decided on a whim to try out the reaction again after having many failures in the past. The procedure is much like the ullmanisation that has been posted on this board, and on rhodium etc. using sodium methoxide, methanol, DMF and CuCl. I was reading hyperlab and saw attempts, and having nothing better to do I gave it one more shot. Methanol was anhydrous as well as DMF, CuCl was fresh, bromovanillin was made by me and was nearly a white powder. However I used sodium methoxide from spectrum which had hardened. This is what I did:

To a 250ml rbf with stirbar and condenser was added 7g sodium methoxide powder (large excess due to unknown purity, not all of it dissolved) followed by 33ml of MeOH. Next a solution of 7g bromovanillin and 700mg of CuCl in 20ml DMF was added. Unlike other attempts I observed no blue/greenish coloration, it stayed beige. It did grow thick with the phenolate however. The mixture was refluxed for 45 minutes with stirring in a boiling waterbath. Next the setup was switched to distillation and over 1hr 30mins methanol was distilled out. At the end it was a much darker red. Solution cooled, added ~100ml water and filtered some bromovanillin and what I assume was copper. Next I acidified the filtrate with HCl, and it turned purple, glittering leaflets started to precipitate. I filtered these, washed with 300ml dH2O and saved them. I still have the remaining filtrate but stopped there for the night. After drying I took a crude melting point with oilbath, test tube and thermometer. They melted at right around 115ºC. I tried to form an adduct with about 200mg of the crystals in a test tube, 2ml of warm methanol and 2 ml of warm sat. metabisulfite solution. Few hours later it seemed to have formed but I have not processed it further.

My question is are these crystals, which weigh 6g, syringaldehyde? I have never had a pure sample before, they have a very low odor I can best describe as woody/sweet but this smell is veryyyyy faint. I made a solution of 200mg in few ml of methanol, added 1ml of ~10% NaOH and it turned yellow, and then oxidized to dark brown upon exposure to air. I realize in preps the solution is usually acidified then filtered, then the filtrate extracted with ethyl acetate or DCM, but I have never read about purple coloration and these crystals are completely insoluble in water and the melting point is close to that of syringaldehyde. Thanks for any help.

Panache - 28-11-2010 at 16:16

At what point is is more efficient to compress air and release it than to 'pump' it with a fan of some sort. The run i have is a 30m, 3inch steel pipe that was once used for fire service (ie water, high pressure). I want to use it to move air from one end of the factory to the other and its just sitting there already mounted.

solo - 1-12-2010 at 08:53

I read someplace that the AlHg reductive amination causes recimization.....of course working to the desired amine via the golden ketone the product will always* be recemic......so no one cares or is concerned, however it's an important point i would like to hear some explanation on how that occurs....there is a pearl at the end of that tunnel......solo

*there are some exceptions , if using a single enantiopure to aminate would be one of them, but maybe not it may just rotate it to the opposite enantiomere, that would indeed be interesting

[Edited on 1-12-2010 by solo]

Random - 7-12-2010 at 10:38

Can I make manganese (ii) acetate from acetic acid and mno2 or do those compounds even react?

ScienceSquirrel - 7-12-2010 at 12:04

Quote: Originally posted by Random

Can I make manganese (ii) acetate from acetic acid and mno2 or do those compounds even react?

The simple answer is no if you are using most grades of manganese dioxide as it is pretty inert.
I would suggest using manganese carbonate, either freshly prepared or purchased, it is quite readily avilalable and a decent grade of acetic acid.

Arthur Dent - 8-12-2010 at 10:15

No you can't make Mn acetate that way, but if you're using the gunk from carbon batteries, some diluted acetic acid will help dissolve and separate some of the zinc impurities, making your MnO2 a bit cleaner. Make sure to wash the MnO2 well with distilled water to remove the remaining acid and dissolved salts.

Robert

Sedit - 10-12-2010 at 13:11

I have a Carbon monoxide tester in my house that will not stop going off. I can not find the source of CO yet I think its more then likely the heater. I want to test to find out the source but I have no idea how I would go about identifing the source.

I need something that would react in the presence of large CO concentrations to preferably produce a color or something.

Any suggestions?

IrC - 11-12-2010 at 23:38

Quote: Originally posted by Sedit

I have a Carbon monoxide tester in my house that will not stop going off. I can not find the source of CO yet I think its more then likely the heater. I want to test to find out the source but I have no idea how I would go about identifying the source.

I need something that would react in the presence of large CO concentrations to preferably produce a color or something.

Any suggestions?

I will assume you have a gas heater. Two causes are so hard to find it will drive you crazy. One is a crack in the burning chamber, not always visible or easy to find. The other is rare and there must be a steady wind. If the top of the furnace exhaust vent is not high enough and the roof is shaped just right a steady wind will drive monoxide back down the vent pumping it into the room. CO in the house is to me dangerous enough it is worth owning a hand held probe. Also a gas detector.

http://cgi.ebay.com/Carbon-Monoxide-meter-CO-gas-meter-detec...

http://cgi.ebay.com/SPD202Ex-Combustible-Gas-Detector-Natura...

Sedit - 12-12-2010 at 00:27

Screwed up part is Im a third generation HVAC technician yet here I am looking for the source of the Carbon monoxide. Its not a cracked heat exchanger like you suggested and I originally though because if so you would see a flutter in the flames of the heater.

I placed the carbon monoxide detector right on the heater which is also next to the water heater, the two prime suspects, and it stopped going off :mad:

this in itself means im completely clueless now as to why this thing is going off like mad everytime the air in the house settles such as when im home alone or when everyone is asleep...

vulture - 12-12-2010 at 14:49

@ Magic Muzzlet

We use to make 3-methoxythiophene from 3-bromothiophene using similar conditions. It only works using freshly prepared NaOMe...

Magic Muzzlet - 12-12-2010 at 15:08

Thanks for your input Vulture and I know it is meant to be freshly prepared, but the solid I got is not bromovanillin, so do you have any idea what it could be?

Sedit - 21-12-2010 at 22:05

Does anyone know if Platinum plated electrodes would be good enough for the Kolbe electrolysis which calls for Pt ability to perform single electron oxidations?

I have found dirt cheep Pt plated wire but dont know if it will work for a Kolbe electrolysis the way I desire. It shouldn't cause to much issue should it since the final contact area is Platinum?

Side note: I found Jewlery that stated Rhodium as the material the pieces where made of,, much of it said rhodium and they are very cheep albeit small, is this really rhodium plated like it says(somecases it dont say plated it suggest its pure) or is it some kind of jewlery talk?

Phosphorus help

Sedit - 22-12-2010 at 14:56

Ok I got another question to ask of you all along with the one above.

I have a phosphate compound that goes by the brand name of Nu Calgon.

Im assuming its Sodium hexametaphosphate. When I heat it with a torch in both a stainless steel and a ceramic crucible to the point where it starts to boil it releases some sort of flamable gas that pops with a green flame.

What is this that is igniting?

The only information I could find is that Sodium hexametaphosphate decomposes in a fire to phosphorus oxides and Sodium oxides but I kind of doubt this is what im seeing.

I don't feel its phosphine either since water should be long gone by the time it reaches its boiling point.

Also when Aluminum is added to the melt it fizzes alot and I get a garlic smell but attempts to trap what I believe is White P fails.

Any suggestions on what this gas is? Even after it cools down when I break up the solid mass the trapped gasses still flare up on contact with air.

not_important - 22-12-2010 at 15:30

Nu Calgon is a company name, they have a number of products including 10 CL phosphate is is basically good old TSP; Calclean Special HD which is a mixture including sodium polyphosphates and metasilicates and a few percent of high boiling organics; and a bunch more. Think you need to be more specific.

Sedit - 22-12-2010 at 15:53

Sorry I thought it was just a name give by the calgon company to this material.

It gives little information on whats in it other then its a special watersoluble phosphate compound for use in micromat system(water purifiers).

Its a glass like substance pretty clear and broken into clear chunks roughly the size of a BB.

Magic Muzzlet - 28-12-2010 at 11:53

1-pentyl-3-(1-naphthoyl)indole, JWH-018.

I have made this compound on 3 occasions and after alkylation in DMSO/KOH or DMF/KOH I receive an amber oil which is slightly gummy, as expected.
But there are reports of the pure substance being a yellowish solid, or even white, while Huffman reports it as the amber gum. Which is it? Does oxidation or some other factor cause it to be an amber gummy oil? I ask because there seems to be no sure answer after a browse on the net.

Over at hyperlab in the cb agonist thread one person received it as a solid, others as oil. The oil is apparently crystallizable from ethanol. I do not need it in a particular form, but I wonder what causes it to take these different forms.

condennnsa - 29-12-2010 at 08:01

I have a question that i can't get my head around.

I saw this video : http://www.youtube.com/watch?v=m4fGIiIpY7A

It's in russian so i don't understand , but they seem to react molten sulfur with H2SO4?

Does sulfur really react with sulfuric acid? What are the products?

mewrox99 - 30-12-2010 at 05:14

This is just my speculation. That the sulfuric acid oxidizes the formed SO2 into SO3 which reacts to form oleum. Sulfur is also formed as a product visible on the testube

3 SO2 + 2 H2SO4 = S + 2 H2S2O7

Random - 30-12-2010 at 15:02

I see everyone is trying to make phenol, but I see no things that can be done with it. What are some reactions or syntheses that I can do with it?

Mixell - 6-1-2011 at 07:24

Well, I understand Russian.
And he is saying that reacting molten sulfur and hot concentrated sulfuric acid produces SO4 (how exactly thats possible- don't have a clue).

[Edited on 6-1-2011 by Mixell]

turd - 6-1-2011 at 10:34

Quote: Originally posted by Magic Muzzlet

1-pentyl-3-(1-naphthoyl)indole, JWH-018.

I have made this compound on 3 occasions and [...] I receive an amber oil which is slightly gummy, as expected.
But there are reports of the pure substance being a yellowish solid, or even white, while Huffman reports it as the amber gum. Which is it?

Sounds like tryptamine chemistry.

It has a long alkyl chain, that usually doesn't help with crystallization. Have you tried cleaning by chromatography with subsequent crystallization from a solvent? IMHO we should take some pride in our products and making nice crystals is part of that.

Magic Muzzlet - 6-1-2011 at 11:10

I lack the resources to do a column at this time, but I have been trying crystallization from ethanol and isopropanol. I just cannot get it to crystallize, it always deposits as little gummy balls on the sides/bottom of the beaker, it is actually very annoying. I'll keep toying with xtallization from ethanol, and get some column supplies which are long overdue. :cool:

kuro96inlaila - 27-1-2011 at 05:15

Err,today i mix KClO3 with H2SO4,It should produce chloric acid and potassium sulfate:

2 KClO3 + H2SO4 → 2 HClO3 + K2SO4

But mine have a gas released in the reaction,a pale yellowish-green gas,I tried to burn it,as I thought it was,it exploded.It is chlorine oxides.

So,which chlorine oxides produced here,and why does it produced?It should not been produced according to chemical equation.Maybe it was produced because I am not using pure sulphuric acid?

ScienceSquirrel - 27-1-2011 at 05:37

The gas is chlorine dioxide, the chemistry is described here;

http://81.207.88.128/science/chem/exps/clo2/index.html

kuro96inlaila - 27-1-2011 at 06:15

thanks!

hkparker - 31-1-2011 at 20:21

Yikes ClO2!

Heres my short question:

Does mercury react with HCl at all? Like does it even in the slightest amount react with conc. HCl? Because I need to clean some mercury from some metal oxides/dissolved metals and I was thinking HCl would be a great way but I do not want to have any remaining mercury salts, so I wont to make sure nothing will happen.

mr.crow - 5-2-2011 at 13:47

Quote: Originally posted by hkparker

Does mercury react with HCl at all?

Nope! reactivity series. Needs an oxidizing agent like HNO3.

BUT things like CuCl2 or FeCl3 might be able to oxidize Hg, sort of like etching copper off PCBs.

hkparker - 5-2-2011 at 14:36

Thank you for the response!

Ok so if iron is my impurity and I produce FeCl3 then... am I no longer safe?

Random - 6-2-2011 at 02:27

Fe + HCl --> FeCl2

FeCl2 and oxygen at acidic conditions ---> FeCl3, it could dissolve some mercury

Fe2O3 + HCl --> FeCl3 again, it could

You can use some reducing agents or something, maybe ascorbic acid with HCl

hkparker - 6-2-2011 at 10:20

Ok thanks. I don't have ascorbic acid, any others you know will work? What about glucose?

SHADYCHASE54 - 6-2-2011 at 20:03

Hello all,
does anyone out there have a good link to a PDF download of, 'Gmelins' it is one of the core I haven't found yet. Any nudge in the right direction would be appreciated.

manimal - 8-2-2011 at 05:38

It is known that benzophenone condenses poorly or not at all in aldol-type condensations, due to it being insufficiently nucleophilic. Question: how might thienophenone (2,2'-dithienyl ketone) perform in such mixed condensations, for example, with acetone under basic conditions?

gsd - 8-2-2011 at 06:57

Quote: Originally posted by SHADYCHASE54

Hello all,
does anyone out there have a good link to a PDF download of, 'Gmelins' it is one of the core I haven't found yet. Any nudge in the right direction would be appreciated.

http://www.archive.org

gsd

12332123 - 9-2-2011 at 06:20

Can anyone suggest a good, readily available stain for the colorimetric determination of N,N-Diethyl-3-methylbenzylamine in the presence of DEET?

[Edited on 9-2-2011 by 12332123]

12332123 - 10-2-2011 at 13:33

Just to get things rolling, how about excess alkaline permanganate?

Nicodem - 10-2-2011 at 14:49

Quote: Originally posted by 12332123

Can anyone suggest a good, readily available stain for the colorimetric determination of N,N-Diethyl-3-methylbenzylamine in the presence of DEET?

Try with some metal salts that only coordinate with amines, but not with amides. Usually the solutions change colour somewhat after coordination. Candidates are solutions of CuSO4, CuCl2, CoCl2, NiSO4, etc.
Do you need this for TLC visualization, for photometric determination or what else? Without further information it is no possible to give much of an advice.

Morgan - 11-2-2011 at 22:20

One time I heated a small pile of ammonium nitrate, potassium dichromate and either aluminum or magnesium powder, I don't recall which. With a direct flame from a propane torch the stuff melted, burned a little and reduced down to some hard nodules about the size of a pea. If you were careful you could heat these hard nodules to a dull red and nothing would happen. But just a little more heat and they would ignite and take off into the air, crackling like some kind of electric discharge whizzing about. I remember one piece seemed to chase me like a bee as I dodged it zinging about. I can't think what it could have been except some kind of thermite-like substance that could resist ignition at such high temperatures.
It kind of reminded me of well melted KNO3 and sugar, how small pieces will take off and whiz about, only these burned much hotter and made a sound like crackling high voltage ball lightning if such a thing existed.
If you have ever melted or lit ammonium nitrate and aluminum powder, it kind of burns for a little bit and then flames out, flashing on and off with a direct propane torch heating method. That's sort of how the stuff did with the dichromate added, like a watery weakly flammable goo as it reduced to a hard rock-like residue.

Sedit - 12-2-2011 at 18:10

I have found Platinum powder in an art shop. Its not much but I wanted to get some thoughts on if its ok to use for some reactions or not. Its only .4 grams for about $4 or something like that and I was thinking about using it to plate some electrodes for use in a kolbe electrolysis or something.

What do ya'll think. Would it be of any use?

vulture - 13-2-2011 at 15:07

Quote:

One time I heated a small pile of ammonium nitrate, potassium dichromate and either aluminum or magnesium powder, I don't recall which. With a direct flame from a propane torch the stuff melted, burned a little and reduced down to some hard nodules about the size of a pea. If you were careful you could heat these hard nodules to a dull red and nothing would happen. But just a little more heat and they would ignite and take off into the air, crackling like some kind of electric discharge whizzing about.

Most probable explanation is intermediary formation of ammonium dichromate, which then decomposed.

gsd - 13-2-2011 at 16:07

Quote: Originally posted by Sedit

I have found Platinum powder in an art shop. Its not much but I wanted to get some thoughts on if its ok to use for some reactions or not. Its only .4 grams for about $4 or something like that ..............

What do ya'll think. Would it be of any use?

The current price of platinum metal is about $1850/oz i.e. roughly $65/gm.

So if nothing else, not a bad investment

gsd

Sedit - 13-2-2011 at 19:50

That cant be right then can it? Im going to have to look at that again. Maybe its .04oz that would make more sense.

12332123 - 14-2-2011 at 11:52

@ Sedit - Unlikely, note that .04oz is even more (over a gram)!

Sedit - 14-2-2011 at 11:58

Lol yeh my fault I ment .04 grams.

Magic Muzzlet - 14-2-2011 at 16:08

I was reading this: http://lambdasyn.org/synfiles/bromovanillin.htm

I noticed in the first example, using KBr in GAA/water/H2SO4 that the KBr is 2eq to vanillin used. Would this not dibrominate the vanillin? Or is it based on available bromine or something, I'm having trouble figuring it out.
If this was subbed with NaBr could it too be used in 2eq to vanillin producing the wanted product?

1281371269 - 16-2-2011 at 13:34

Could anyone explain what these are:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110...

They're definitely stillheads, because they have two male joints and anyway basically look the same as splash stillheads. But what are the other bits for? The tube coming off of the side looks like a vacuum outlet, but surely this should be on the receiver? And what about the tube coming down from the bottom, what's that supposed to do?

DJF90 - 16-2-2011 at 19:34

Steam distiallation heads. The side tube is attached to steam source, which leads down to into the flask. The vapour then passes through the splash head, and to the condenser that you'll have to attach.

UnintentionalChaos - 16-2-2011 at 22:32

Quote: Originally posted by Mossydie

Could anyone explain what these are:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110...

They're definitely stillheads, because they have two male joints and anyway basically look the same as splash stillheads. But what are the other bits for? The tube coming off of the side looks like a vacuum outlet, but surely this should be on the receiver? And what about the tube coming down from the bottom, what's that supposed to do?

Looks like equipment for kjeldahl nitrogen determinations to me. The tube might be for air flow to carry the last of ammonia into the reciever. I'm just guessing though.

DJF90 - 16-2-2011 at 23:23

Don't believe me then... http://www.scilabware.com/Adapters/Steam-distillation-head/p...

1281371269 - 17-2-2011 at 11:10

Thanks for the help

SHADYCHASE54 - 18-2-2011 at 18:15

Hello all,

I just have a couple quick questions firstly, I have some cation exchange resin in the H+ form and i was wondering if anyone knows how I may determine the resins exchange potential per/cm3? The resin type is Amberlite IRN-77.

Secondly, would someone out ther is S.M land reccomend a good book that encompasses the theory and thus applications of the various exchange media? thanks in advance for any help.
SHADY..

SHADYCHASE54 - 19-2-2011 at 14:51

Does anyone have any ideas?

Random - 23-2-2011 at 02:01

I read that if I react phtalic acid and phenol i get phenolphtalein. What would happen if I would react phenol with terephtalic acid, would I get phenolphtalein or maybe phenolterephtalein exists? WOuld phenolterephtalein also work as indicator?

UnintentionalChaos - 23-2-2011 at 20:06

Quote: Originally posted by Random

I read that if I react phtalic acid and phenol i get phenolphtalein. What would happen if I would react phenol with terephtalic acid, would I get phenolphtalein or maybe phenolterephtalein exists? WOuld phenolterephtalein also work as indicator?

You need to use phthalic anhydride, not phthalic acid. The reaction is a friedel crafts acylation followed by a second condensation to yield a tertiary alcohol that cyclizes to a lactone The indicator's ability to change colors relies on the ortho carboxylate group.

Phthalic acid is cheap and decent conversion to the anhydride can be had by simple heating.

To be fair, I ran a very small scale version using sulfuric acid, phenol, and phthalic acid. Enough was formed that I could get very intense color changes with the diluted reaction mixture, but not enough to isolate any product

EDIT: might as well add a question of my own. I remember something about selective sulfonation of mixed xylenes to seperate the isomers, but my search-fu seems to be weak tonight. Does anyone have this reference?

[Edited on 2-24-11 by UnintentionalChaos]

Sedit - 28-2-2011 at 08:42

Does anyone know if Platinum plated electrodes could be used in a Kolbe electrolysis, I have yet to find someone local to sell me a small amount of Pt wire but I did manage to get ahold of some plated wire with a coating 2 microns think.

BTW: That other Platinum powder I spoke of earlier in this thread was a bust. I checked it out and on the back it clearly states it contains Copper so I highly doubt there is much Pt if any in that powder at all. That would explain the .4oz of Platinum powder for $5.

Morgan - 1-3-2011 at 10:52

Is there a way to test for water in methanol? I sometimes buy 5 gallon amounts from a speed shop/racing store and I got the last of a 55 gallon drum. It was very hot and humid that day and I have to wonder how much water the methanol absorbs every time they pump some out. It didn't seem to burn as well as before. Even with just a little water in methanol, it can affect how some engines/devices run. I'm talking about less than 5% water.
I use methanol a lot, and sometimes for small experiments I will buy some HEET just to make sure the methanol hasn't absorbed water from the air.
Or is there an easy way to dehydrate it completely without doing some methoxide reaction?

Lambda-Eyde - 1-3-2011 at 11:10

Anhydrous copper sulfate? Alcohols are usually dehydrated with CaO or K2CO3.

Nicodem - 1-3-2011 at 11:17

Quote: Originally posted by Morgan

Is there a way to test for water in methanol?

You can do a Karl-Fischer titration to get an exact measurment, but that requires buying the required solution (Hydranal). If you need just a rough qualitative test you can add your methanol dropwise into some toluene. If there is much water inside you will get some turbidity instead of a clear solution (the turbidity will disappear once you add enough methanol). I guess you could actually make this a primitive quantitative test if you make a calibration curve with methanol solutions of known water content. However, it will not show anything if your methanol only has little moisture, though you could greatly enhance the sensitivity by using hexane/toluene mixtures instead (white spirit or any other OTC source of alkanes will do instead of hexane, but some toluene must be present because methanol is not fully miscible in alkanes).
Another primitive test using only OTC materials is adding some anhydrous CuSO4 to methanol and letting it stay over night. If there is some water present, the salt will partially colourize blue. Anhydrous white CuSO4 can be made by heating CuSO4.5H2O.

Morgan - 1-3-2011 at 14:33

Thanks, maybe I will try the copper sulfate. I once made some anhydrous CuSO4 , it's funny how it doesn't suddenly reuptake the water previously driven off.
The toluene turbidity test seems good too. Has anyone heard of using cornstarch to absorb water or what percentage it would take out.
The other day I tried a few crystals of KMNO4/purple salt, but it was old in a moist environment and I didn't even know if it was soluble in methanol. if it would be worth a try to detect water.
Another thing, I once dehydrated some magnesium sulfate just to see how it would burn with powdered magnesium and it burns fine, but I can't recall, but it seems like it too was slow to rehydrate.

[Edited on 2-3-2011 by Morgan]

497 - 2-3-2011 at 21:41

Does anyone know if PdCl2 on carbon will work in a catalytic transfer hydrogenation? According to Orgsyn you can toss it directly into a standard H2 gas hydrogenation as long as a little HCl won't hurt, but I'm not convinced it would work the same for a CTH. I couldn't find any word online about it. Thanks.

Morgan - 6-3-2011 at 10:21

With methanol a platinum catalyst will produce some formadehyde. What will platinum catalysts produce when reacted with isopropyl alcohol? And with ethanol is it just acetyldehyde? Or are there other byproducts?
I recall Dobereiner made a vinegar producing lamp using platinum and ethanol(?) somehow.

[Edited on 6-3-2011 by Morgan]

Morgan - 6-3-2011 at 18:57

The reason I asked is I saw this video of a catalytic lamp that runs on isopropyl alcohol and platinum.
http://www.youtube.com/watch?v=oiPwzYsldfk

"What is Ashleigh & Burwood Lamp Fragrance made from?"
"The basis of the Lamp Fragrance, and the important fuel which keeps the catalytic process working, is an alcohol called isopropyl alcohol. A very common alcohol, it is the same form of alcohol which is commonly used in hospital anti-bacterial handwashes for example. The other ingredients are distilled water, and the fragrance compound itself."
http://www.ashleigh-burwood.co.uk/lamps-faq.html

"I find the fragrance too strong, what can I do?"
"Firstly, be sure that you are not using the lamp for extended periods of time, especially in smaller rooms and when the door(s) and window(s) are closed. Fragrance Lamps are incredibly effective at fragrancing the air (unlike a room spray for example where the fragrance droplets will fall to the ground after a few minutes) and you will find that the fragrance lingers for several hours in the room after the lamp has been stopped. If you feel that it is the fragrance itself which is too strong for your liking, then it is possible to dilute down one of our Lamp Fragrances, using the Neutral (unfragranced) variety – this is product code PFL900 for the 250ml bottle, and PFL928 for the 500ml bottle. You can mix in any ratio you like until you find the level which best suits you."
http://www.youtube.com/watch?v=i4644kytStI&feature=relat...

[Edited on 7-3-2011 by Morgan]

Morgan - 7-3-2011 at 07:55

I wonder what the adhesive coating technique was?
"The filter paper wrapping of 1823 was succeeded
by a dried and ignited mixture of platinum
sponge and potters’ clay; and an improved
version of the Dobereiner lamp had its
platinum sponge applied in an adhesive
coating on a coil of platinum wire."
http://www.platinummetalsreview.com/pdf/pmr-v9-i4-136-139.pd...

Morgan - 7-3-2011 at 08:16

Here's the tidbit I sited about making acetic acid from ethanol. Still I wonder what isopropyl alcohol makes when reacted with platinum?
"In 1821, after reading Edmund Davy’s article
in a German translation which appeared in that
year, Döbereiner repeated this experiment and
found that the ethanol was oxidised to acetic
acid. Because the platinum was not consumed,
he suggested that the reaction could be used
“for the large-scale preparation of acetic acid”
(Essigsäure) (27), and he even designed a vinegar
lamp (Essiglampe), in which ethanol was supplied
by a cotton wick to a small funnel containing
platinum black."
http://docserver.ingentaconnect.com/deliver/connect/matthey/...

[Edited on 7-3-2011 by Morgan]

Morgan - 7-3-2011 at 11:02

This is a picture with some 91% isopropyl alcohol reacting with my platinum gauze. I couldn't tell by the smell what the products of combustion might be.

[Edited on 7-3-2011 by Morgan]

Attachment: phpHOUd45 (65kB)
This file has been downloaded 957 times

Pages: 1 2 3 4 .. 8