Sciencemadness Discussion Board - The short questions thread (3)

The short questions thread (3)

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benzeentje - 20-3-2012 at 10:58

Hi all, i'm trying to extract caffeine without chloroform or other halogen-alkanes. I have thinner (mostly toluene), terpentine, and white spirit. Wich one is best, considering this caffeine doesnt need to be edible?

I was thinking thinner (because of the toluene) but it has a boiling point of +-110°C -.-

Why not to use ether?

Because i have none. I have acetone too, but this is apperently used as recrystalization solvent instead of extraction solvent as most of the inpurities in coffee dissolve in acetone too.

Endimion17 - 21-3-2012 at 04:31

Why are English-speaking people almost always saying "sodium metal", "titanium metal", instead of sodium and titanium? I don't see anyone saying "iron metal" when chemistry is discussed. It's iron, and it's obvious it's a metal.

Is the "_metal" addition required by BE/AE chemical nomenclature (it sure isn't required by the IUPAC standards), or is it a consequence of proliferation of errors over the Web? I ask that because I've had more than a few brushes with pre-Internet English chemical literature, and such linguistic constructs are very rare.
Also, the reagent bottles always say stuff like "CALCIUM", and beneath, written in small fonts, is "metallic" or "metal". If it's written in Latin, it says "metallicum", but always as an additional info. The name of the substance isn't "CALCIUM METAL", it's "CALCIUM".

Since the Web has made a huge boom on the society, constructs such as "CADMIUM METAL" began replacing older, plain and simple "CADMIUM". Why is that? It sound stupid, at least to me. Reminds me of errors that accumulate and soon become the "truth".
As it's something that is boosted by .com companies that sell compounds online. Sodium has become, from a notoriously difficult to obtain material which I wanted to own since I saw its photos in elementary school, to a material easy to buy online, for tossing in lakes and toilet bowls by kids whose chemistry knowledge is scarce. Everytime I hear "sodium metal", I instantly think of those kids.

I've grown up with bottles of "sodium", "natrium", "natrij", "sodio", etc., so yeah, I'm puzzled.

[Edited on 21-3-2012 by Endimion17]

ibro - 29-3-2012 at 12:13

Does anyone know which gas could be used to boost a car beside N20???

ibro - 29-3-2012 at 12:15

Can someone tell me a proper way to dispose used engine oil?

solo - 29-3-2012 at 17:49

.....can someone assist me innaming this compound.......thanks.....solo

C6H5-CH2-CH(COCH3)-CH3

NOte ....i edited because i wrote it wrong....this is now correct!

[Edited on 30-3-2012 by solo]

smaerd - 29-3-2012 at 22:18

I don't believe that the compound you have written is possible how it is written. In order for a CH-C bond to be possible dangling off of a benzene ring is if there were to be a double bond. So, C6H5-CH=C(C-CH3)-CH3. Now in order for the C-CH3 to be possible, there would have to be some kind of triple bond from the other adjacent carbon(not the CH3). Which leads to a hexavalent carbon:
C6H5-CH=C(=-C-CH3)-CH3
___________^^Triple bond (hopefully this posts okay)

Unless you meant C6H5-CH2-CH(-CH2-CH3)-CH3 ; in which case the name would be (2-methylbutyl)benzene. Unless I am severely misinterperating something here(entirely likely).

edit : solo I really reccomend checking out ACD labs marvin sketch, it has an awesome IUPAC naming functionality and drawing structures is a breeze. It works on all operating systems I believe as well and is free with limited functionality.

[Edited on 30-3-2012 by smaerd]

bbartlog - 30-3-2012 at 05:09

Quote: Originally posted by ibro

Can someone tell me a proper way to dispose used engine oil?

Bring it to some place that will dispose of it. Depends on what country you're in... here in the USA I might bring it to the local Tractor Supply store. I think (not sure) that any place that sells motor oil has to take back used oil for disposal, up to a certain quantity.
However, assuming that your question is more oriented towards science madness than a practical solution ('How can *I personally* render my used motor oil environmentally innocuous?'), I might suggest a Babington burner. Google it.

fledarmus - 30-3-2012 at 12:03

Quote: Originally posted by solo

.....can someone assist me innaming this compound.......thanks.....solo

C6H5-CH2-CH(COCH3)-CH3

NOte ....i edited because i wrote it wrong....this is now correct!

[Edited on 30-3-2012 by solo]

Looks like 3-methyl-4-phenylbutan-2-one to me

solo - 30-3-2012 at 16:56

Quote: Originally posted by fledarmus

Quote: Originally posted by solo

.....can someone assist me innaming this compound.......thanks.....solo

C6H5-CH2-CH(COCH3)-CH3

NOte ....i edited because i wrote it wrong....this is now correct!

[Edited on 30-3-2012 by solo]

Looks like 3-methyl-4-phenylbutan-2-one to me

....that is correct....thank you...solo

Chordate - 31-3-2012 at 22:45

Quote: Originally posted by Endimion17

Why are English-speaking people almost always saying "sodium metal", "titanium metal", instead of sodium and titanium? I don't see anyone saying "iron metal" when chemistry is discussed. It's iron, and it's obvious it's a metal.

Is the "_metal" addition required by BE/AE chemical nomenclature (it sure isn't required by the IUPAC standards), or is it a consequence of proliferation of errors over the Web? I ask that because I've had more than a few brushes with pre-Internet English chemical literature, and such linguistic constructs are very rare.
Also, the reagent bottles always say stuff like "CALCIUM", and beneath, written in small fonts, is "metallic" or "metal". If it's written in Latin, it says "metallicum", but always as an additional info. The name of the substance isn't "CALCIUM METAL", it's "CALCIUM".

Since the Web has made a huge boom on the society, constructs such as "CADMIUM METAL" began replacing older, plain and simple "CADMIUM". Why is that? It sound stupid, at least to me. Reminds me of errors that accumulate and soon become the "truth".
As it's something that is boosted by .com companies that sell compounds online. Sodium has become, from a notoriously difficult to obtain material which I wanted to own since I saw its photos in elementary school, to a material easy to buy online, for tossing in lakes and toilet bowls by kids whose chemistry knowledge is scarce. Everytime I hear "sodium metal", I instantly think of those kids.

I've grown up with bottles of "sodium", "natrium", "natrij", "sodio", etc., so yeah, I'm puzzled.

[Edited on 21-3-2012 by Endimion17]

I think this primarily has to do with specificity. There are a lot of biochemists and biologists who also discuss sodium channels and sodium/potassium pumps and clearly they are not talking about the metal. Halogens have an easy suffix to distinguish between their elemental and ionic states, and those that were known to have exotic oxidation states before the formalization of modern oxidation state nomenclature still use common names like "periodinane". Since metals are capable of attaining such a wide variety of oxidation states and still retaining ionic character and the names get increasingly ridiculous, more and more people have moved over to the [element](oxidation state) state nomenclature.

But for sodium, calcium, and a few others, its just as easy to specify the ground state oxidation state by just saying "metal" and I think it has spread because its both easy and scientists love to use precise jargon when they can.

barley81 - 4-4-2012 at 15:15

I have 2 gallons of unopened HTH 10% sodium hypochlorite pool chlorinator. I bought it last summer, and stored it in the basement (cool and dark). How much do you think it has degraded? Is it still useable?

Nathaniel - 5-4-2012 at 07:49

Open it and carefully smell it - if it stinks like chlorine there's still some left

This is just a quick test - you can pour some technical HCl on it (10ml +10ml for example)...if yellowish-green chlorine evolves the solution is enough concentrated for most uses... Be careful when doing this (do it outside, because chlorine can be quite nasty).

It's hard to guess but if you want to know the specific concentration and have the chemicals and equipment you can titrate it as well (I once did it with bleach): dissolve some iodide (1-2 grams KI) in water and add a few drops of sulfuric acid (more if it's not concentrated). Add an approximate volume of your solution (about 15ml). The solution turns brown because of iodide. Titrate with thiosulfate solution until the colour fades-then add some starch (turns blue) and continue titrating until it becomes almost colourless.
If you just need it for cleaning or something than testing it with HCl is enough

Endimion17 - 6-4-2012 at 14:55

Quote: Originally posted by Chordate

Why being specific is some things are obvious? Biochemist obviously won't talk about metallic sodium.

What about "chlorine gas"? What's with the "gas"? It's obviously a gas. And why not "chlorine nonmetal"?
And bromine, iodine? You never hear "bromine liquid" or "iodine solid", although there's a huge and important difference between the elemental states and the elements, a difference often used.

I don't know, dude. I've layed lots of arguments here to back up my hypothesis that this has something to do with n00b proliferation.

Quote: Originally posted by barley81

I have 2 gallons of unopened HTH 10% sodium hypochlorite pool chlorinator. I bought it last summer, and stored it in the basement (cool and dark). How much do you think it has degraded? Is it still useable?

It's fine.

[Edited on 6-4-2012 by Endimion17]

bbartlog - 6-4-2012 at 17:33

Quote: Originally posted by barley81

Usable for what? As a rough estimate I'd say it is likely to have lost 25% of its strength, i.e. it will function more like 7.5% sodium hypochlorite and have a bit of sodium chlorate contamination as well.

dann2 - 13-4-2012 at 03:50

Can H₂S be used to destroy Chlorate contamination in Perchlorate?
Dann2

smaerd - 16-4-2012 at 22:12

Can NMP be safely distilled without a vacuum? If so, how about in a heating-mantle?

Mik229 - 19-4-2012 at 08:16

If nitrogen dioxide is bubbled through alkylhalide solution in aprotic polar solvent, is the only product nitrite or mixture of nitrite and nitroalkanes?

solo - 20-4-2012 at 05:42

Th other day i was making lead acetate and because it dries inn any surface quite well i had some on my spatula so i decided to remove it by dipping it into a 50% solution of hydrogen peroxide....to my surprise it started fizzing and making foam and heating the beaker extremely hot....and exothermic reaction but can't figure out the reaction .......

Lead(II) acetate (lead diacetate), Pb(CH3COO)2 +H2O2........2 PbO + GAA? not sure since this is the the way it was synthesized

Endimion17 - 20-4-2012 at 05:58

What's up with this over-usage of little known (or custom, made up) abbreviations on this forum? They don't really make life easier.

Regarding the lead acetate thingy, I'd pay more attention to the 50% (holy shit) hydrogen peroxide decomposing and boiling. That's why the solution went extremely hot.
If any lead(II) oxide was formed, it would be obvious by the precipitate.

Nicodem - 20-4-2012 at 06:24

Solo, some metals and their salts catalyze the exothermic decomposition of hydrogen peroxide. You should be more careful with 50% hydrogen peroxide. As far as I know, concentrations of 60% and above can cause dangerous runaway decompositions (even explosions in closed vessels on a large scale). Hydrogen peroxide with a metal catalyst can be used as a rocket fuel (see http://www.peroxidepropulsion.com/article/5).

Morgan - 22-4-2012 at 16:46

Does anybody know how and what the gel is made of in a gel mattress? I read it's made from plant and mineral oil but that is rather scant. It's combined with polyurethane foam or bonded on top of it, I saw two samples the other day.
The elastomer reminds me of the texture of this toy, kind of sticky and very easily deformed. The gel is supposed to provide some cooling to the mattress, as polyurethane foam can be hot to sleep on.
http://en.wikipedia.org/wiki/Wacky_WallWalker

[Edited on 23-4-2012 by Morgan]

Chemstudent - 28-4-2012 at 11:00

I'm taking Organic Chemistry I this summer at my University. I have a good 3 weeks - 1 month before I take the class officially. I just completed Gen. Chem I with a B, and had a good understanding of all the material. What is the best strategy for preparing my knowledge base for Organic Chem so that I find everything already easy or familiar in 1 month? I've already studied and understood the little basics Alkanes/enes/ynes/cyclos & the functional groups + conform/config/constitution of emil fischer projections. But thus far that is it. I figured just watch the Yale or other University open courseware and take notes.

DDTea - 28-4-2012 at 12:06

Quote: Originally posted by Chemstudent

What is the best strategy for preparing my knowledge base for Organic Chem so that I find everything already easy or familiar in 1 month? I've already studied and understood the little basics Alkanes/enes/ynes/cyclos & the functional groups + conform/config/constitution of emil fischer projections. But thus far that is it. I figured just watch the Yale or other University open courseware and take notes.

Mastering the basics will significantly reduce the learning curve. Every O. Chem. professor is going to beat nomenclature and functional groups into your head, so you were right to focus on it.

Next, start memorizing pKa values of common functional groups. This is a good table for that: http://mysite.science.uottawa.ca/aflynn/CHM2120_files/pKa_of... . Since proton transfers are the fastest reaction in organic chemistry, they are always the first reaction in a mechanism. Understanding which groups will be protonated and deprotonated is critical to rationalizing reaction mechanisms.

Review your thermodynamics and acid-base chemistry. These are also very important ideas in organic chemistry.

Start reading about NMR and Infrared spectroscopy. There are plenty of introductory resources available online and that is all you will need at this point. Just learn (memorize) typical chemical shifts in NMR and absorption frequencies in IR, because that's another thing that introductory courses will grill you on.

Good luck!

smaerd - 29-4-2012 at 07:15

Resonance is kind of tricky for some people. It's pretty intuitive once you know which groups are electronegative, etc. If you learn resonance structures and hybrids before stepping in ontop of what you already know, you'll be completely set!(in my opinion)

solo - 10-5-2012 at 06:24

I recently found the need to prepare some DIB, ......one method in found in Molecule
Journal....

Molecules 2005, 10, 217-225

ISSN 1420-3049
http://www.mdpi.org
Application of [Hydroxy(tosyloxy)iodo]benzene in the Wittig- Ring Expansion Sequence for the Synthesis of β-Benzocyclo- alkenones from α-Benzocycloalkenones
Michael W. Justik and Gerald F. Koser*
:.........................

Typical Synthesis of (Diacetoxyiodo)benzene
A solution of 32% (w/v) peracetic acid (100 mL, 421 mmol) in acetic acid was added dropwise with mechanical stirring to a cooled flask (15 oC) containing iodobenzene (65.28 g, 320.0 mmol), over a period of 1 hour. The rate of addition was adjusted to keep the temperature of the reaction mixture between 25-30 oC. Mechanical stirring was continued for 4 hours during which time a white precipitate separated. Water (100 mL) was added to facilitate precipitation and to dilute any remaining oxidant. The solid was isolated by vacuum filtration, washed with water (2 x 100 mL) and ether (150 mL), dried over P2O5 in a vacuum dessicator overnight and identified as (diacetoxyiodo)benzene; yield 94.86 g (92%); mp 160-161 °C (lit. [9] mp 159-161 °C).

.....it seems straight forward, any pitfalls i should be aware of...?....thanks...solo

Hexavalent - 16-5-2012 at 09:04

Is the following adequate for handling potassium dichromate (VI);

Goggles
Nitrile gloves
Lab coat

I've read the MSDSs but TBH most of them are quite vague with regards to laboratory handling. I will be using, say, 3g at most at any one time.

Is this sufficient then for handling this compound not in a fumehood?

ScienceSquirrel - 16-5-2012 at 09:20

Quote: Originally posted by Hexavalent

Is the following adequate for handling potassium dichromate (VI);

Goggles
Nitrile gloves
Lab coat

I've read the MSDSs but TBH most of them are quite vague with regards to laboratory handling. I will be using, say, 3g at most at any one time.

Is this sufficient then for handling this compound not in a fumehood?

To be honest, more than enough.
The point is to avoid slopping it on your skin, inhaling aerosols etc.
Most MSDS's are exercises in arse covering.
Think about sulphuric acid; compare say 2.5 litres of hot concentrated acid and 5ml of cold dilute acid.
The MSDS is the same but the hazard associated with the first is a lot greater.

Hexavalent - 16-5-2012 at 10:01

Thanks, SS. That confirmed a lot for me, and I have gained my confidence in handling these materials... . the MSDS was enough to put me off initially.

Can anyone who has used this material offer any specific advice on its handling? My salt is in the form of a medium-fine powder. Any good ways to reduce the creation of aerosols?

barley81 - 17-5-2012 at 10:43

Question: On a 2L bottle of nitric acid, the pouring ring is cracked and the inside of the cap has a few cracks in the liner inside the circle-like impression made by the mouth of the bottle. Otherwise, the cap is fine. Do I need to replace the pouring ring or the cap? If so, where can I buy a new pouring ring?

Roger86 - 24-5-2012 at 19:28

What is the best haircolor for a person who loves his natural color as much as he loves hydrogen peroxide?

I know i can get cheaper from aquarium and hardware stores, but i'm in rural place and tried the pharmacy already, they have 1% stuff for 4,5€/100ml.

plante1999 - 29-5-2012 at 16:52

How can-I test for calcium cyanamide without silver.

hyfalcon - 30-5-2012 at 16:52

Quote: Originally posted by Hexavalent

Thanks, SS. That confirmed a lot for me, and I have gained my confidence in handling these materials... . the MSDS was enough to put me off initially.

Can anyone who has used this material offer any specific advice on its handling? My salt is in the form of a medium-fine powder. Any good ways to reduce the creation of aerosols?

Just make sure to turn your electrolytic cell off and let it rest a few seconds, minute or two, and let the out-gassing settle before taking your lid off. This will eliminate any aerosols.

smaerd - 6-6-2012 at 15:37

Anyone have any tips for drying molecular sieves at home?

Panache - 9-6-2012 at 03:53

Quote: Originally posted by smaerd

Anyone have any tips for drying molecular sieves at home?

the microwave works well followed by application of a vacuum (decent vane pump vacuum or better, be careful though as the first time i tried it the heat of the sieves broke the annealed glass plate of the microwave. place them on any standard dinner plate.

i'm fairly certain you cannot overheat them in a microwave, so use something like a 30min cycle at 50%power. the domestic microwaves simply have one duty cycle which they switch on and off more or less frequently depending on the power cycle.

there is no quick drying procedure for mol sieves, it takes time.

there is a paper around concerning it from like a laboratory education type journal but i don't have it at present.

Panache - 9-6-2012 at 03:56

Just checking......does leaving a 240-120V stepdown transformer connected to the 240V supply consume any or much power, it ever so slightly hums and is warm and is really old, big and useful as it has one of every 110/120V plug on it

watson.fawkes - 9-6-2012 at 08:06

Quote: Originally posted by Panache

Just checking......does leaving a 240-120V stepdown transformer connected to the 240V supply consume any or much power, it ever so slightly hums and is warm

If it's warm, it's consuming power, just like a space heater does.

When there's no load on the secondary, the primary of a transformer acts like a choke. The wire within the coil has resistance, just like any other wire. It's not like a dead short, because the coil also acts as a ballast, limiting current.

Panache - 13-6-2012 at 05:19

Quote: Originally posted by watson.fawkes

Quote: Originally posted by Panache

Just checking......does leaving a 240-120V stepdown transformer connected to the 240V supply consume any or much power, it ever so slightly hums and is warm

So i guess that excludes it as a culprit in my ridiculous spike in energy costs from $850 a quarter to ~$2000k.
Personally i think the estimated bills are to blame. Get this because my meter is inside if i'm not around the bill gets estimated. Go back 7 quarters, almost two years, my last meter read, $800, the next six estimated bills $2000-$2500each. I didn't stress i considered it a form of savings.
Finally get a meter reading waiting by the post box every day waiting for my $10K cheque, never arrives.
Two months later decide to give them a call, what happened, i ask, 'Oh if you want a reissued account you have to request one for each bill?'
I ask, but what if you had underestimated? Guess what, bill will issue automatically, i love corporate philosophy. I request bills to be reissued.
Forward twelve months, countless phone calls, million assurances, still no reissued account. i go nuts, following week amended accounts arrive, guess what, over six quarters they claim to have estimated completely accurately, to the cent! i'm laughing at the person on the phone saying come on, their rebuttal 'well its not impossible'
hello electricity ombudsman.

mineralman - 16-6-2012 at 02:44

Quote: Originally posted by Roger86

What is the best haircolor for a person who loves his natural color as much as he loves hydrogen peroxide?

I know i can get cheaper from aquarium and hardware stores, but i'm in rural place and tried the pharmacy already, they have 1% stuff for 4,5€/100ml.

Do dairy farmers use it to steralise the glass in the dairy?
hydroponics mail order 17.5% - 35%

[Edited on 16-6-2012 by mineralman]

smaerd - 17-6-2012 at 23:30

In general phenols are not prone to carboxylation/oxidation from typical atmosphere in acidic solutions right? Or should inert atmosphere always be used?

In basic solution they go the way of kolbe schmitt (carboxylation via E.A.S.) but this is because of the phenolate.

Roger86 - 18-6-2012 at 15:48

Quote: Originally posted by mineralman

Do dairy farmers use it to steralise the glass in the dairy?
hydroponics mail order 17.5% - 35%

I tried the haircolor stuff, talk about useless stuff.I was under the impression that those would be somewhat diluted H2O2 but the label had at least 15 ingredients, the stuff was horrible for my use.

I just had to drive to city and buy pure stuff from big pharmacy.It cost me 40€ for 1L of 30%, but it was what i wanted in the first place

Vikascoder - 24-6-2012 at 23:48

I posted this question in sucrose octanitrate thread but no one replied a proper answer for this thread . My question is What is the detonation velocity of sucrose octanitrate and can it be used as a booster charge in detonators

weiming1998 - 25-6-2012 at 02:52

Quote: Originally posted by plante1999

How can-I test for calcium cyanamide without silver.

Calcium cyanamide decomposes on contact with water (http://en.wikipedia.org/wiki/Calcium_cyanamide), so just drop in water. If gases are formed, bubble them through water and pour a solution of Cu2+ ions in. If it is cyanamide, the solution should turn deep blue. Then react the resulting solid with HCl(aq). CO2 gas should evolve, which you can test whether it is CO2 or not with lime-water. No need for silver.

[Edited on 25-6-2012 by weiming1998]

Diablo - 25-6-2012 at 21:49

Is anhydrous mgso4 a suitable drying agent for isopropyl alcohol.

bbartlog - 26-6-2012 at 12:11

Yes, in the sense that it will not react with it. However, if you need it to be really dry (e.g. for synthesis of aluminum isopropoxide or the like) then it is not a strong enough drying agent and you would need to follow up with something else. I have dried IPA with MgSO4 in the course of synthesizing isopropyl chloride, and in this context, where a small amount of residual water is no problem, it worked just fine.

Diablo - 26-6-2012 at 14:34

Thank you

LiHMDS - 30-6-2012 at 20:18

Hi everyone!
I have a slightly stupid problem with some household - today I found my bottle of few kg bromine is pretty closed - glass stopper is stuck in this fn bottle. I tried to carefully knock, turn etc, nothing helps. Is there any 'smart' way to open this joint taking on discount all situation?

[Edited on 1-7-2012 by LiHMDS]

solo - 6-7-2012 at 13:06

In the reduction of carbamates.....in the article,
Preparation of Methyl N-Substituted Carbamates from Amides through N-Chloroamides
Gene A. Hiegel and Tyrone J. Hogenauer

http://www.chembbs.com.cn/bbs/File/UserFiles/UpLoad/20090924...

.....the Chlorinated amine is treated with sodium methoxide to make the methyl carbamate.....

my question, i have sodium ethoxide, can this be used and have the same result?

[Edited on 6-7-2012 by solo]

[Edited on 6-7-2012 by solo]

RadioTrefoil - 11-7-2012 at 22:44

Quote: Originally posted by LiHMDS

Hi everyone!
I have a slightly stupid problem with some household - today I found my bottle of few kg bromine is pretty closed - glass stopper is stuck in this fn bottle. I tried to carefully knock, turn etc, nothing helps. Is there any 'smart' way to open this joint taking on discount all situation?

What you have experienced is a "frozen joint". It happens when ground glass joints haven't been lubricated with silicone grease or petroleum jelly. Here's a link to wikipedia article that may help you:

http://en.wikipedia.org/wiki/Ground_glass_joint#Frozen_joint...

Pyrophoric copper?

RadioTrefoil - 11-7-2012 at 22:51

Hey peeps,
Today I was experimenting with Iron powder divided so finely it was pyrophoric. I synthesised the powder from thermal decomposition of Iron(II) oxalate.

FeC2O4 → Fe + 2CO2

I was wondering if the same pyrophoricity could be observed with Copper powder formed with the same method of thermal decomposition of the oxalate salt, or is copper too unreactive to be pyrophoric in this case?

Mixell - 12-7-2012 at 02:47

Some guy on this forum has created pyrophoric copper from decomposition of copper acetate, so I think it is possible.

Nicodem - 12-7-2012 at 03:56

Quote: Originally posted by solo

In the reduction of carbamates.....in the article,
Preparation of Methyl N-Substituted Carbamates from Amides through N-Chloroamides
Gene A. Hiegel and Tyrone J. Hogenauer

http://www.chembbs.com.cn/bbs/File/UserFiles/UpLoad/20090924...

.....the Chlorinated amine is treated with sodium methoxide to make the methyl carbamate.....

my question, i have sodium ethoxide, can this be used and have the same result?

Many bases can be used for the Hofmann rearrangement. Alkali hydroxides are most commonly used when the isocyanate is to be quenched directly to the amine. If carbamates are the target, then you would want to avoid bases that could potentially give mixtures of products. For example, if you use sodium ethoxide in methanol, then the main product should be the methyl carbamate, but there will be some contamination with ethyl carbamate as well. Depending on the nature of the product (is it recrystallizable?) it might be tedious to remove this side product. In such a case, it would be better to use sodium hydroxide in methanol. The main product would still be the methyl carbamate, but there would also be some contamination with the amine (and potentially of the N,N'-dialkylurea). However, the amine can easily be washed away during the extractive work-up.

Another solution is to prepare sodium methoxide from your sodium ethoxide by dissolving it in absolute methanol and rotavaping to dryness.

Perhaps the simplest solution of them all is to prepare sodium methoxide from sodium or sodium hydroxide. There are methods described on the forum. Ullmann posted what is probably the simplest of them all, which is just drying the methanolic NaOH with molecular sieves.

Boron Trioxide - 12-7-2012 at 16:13

I have a quick question:

I understand that mixing chlorate containing compositions with sulphur is dangerous, though is there any danger with mixing it with a sulfate, namely copper sulfate, for a blue flame?

[Edited on 13-7-2012 by Boron Trioxide]

RadioTrefoil - 14-7-2012 at 01:31

Quote: Originally posted by Boron Trioxide

I have a quick question:

I understand that mixing chlorate containing compositions with sulphur is dangerous, though is there any danger with mixing it with a sulfate, namely copper sulfate, for a blue flame?

[Edited on 13-7-2012 by Boron Trioxide]

Sulfate is not a reducing agent like elemental sulfur. It would not burn at all by itself. Chlorate is a very unstable oxidiser, so pretty much any reducer/chlorate mixture will be dangerously unstable. Copper chloride mixtures would probably be the best blue colourant.

[Edited on 14-7-2012 by RadioTrefoil]

Boron Trioxide - 14-7-2012 at 19:39

Thanks for the response, though another question just occurred to me.

For pyrotechnics would it be possible to use Potassium peroxymonosulfate as an oxidizer? Wikipedia doesn`t list its decomposition temperature, while mentioning that is an oxidizer.

Possible Decomposition:
KHSO5 => KOH + SO2 + O2
This seems a bit unlikely but I am unsure of any other decomposition routes more likely.

Sorry if this question is ridiculous in some way, I checked nobody has mentioned this before.

RadioTrefoil - 17-7-2012 at 23:34

Quote: Originally posted by Boron Trioxide

Thanks for the response, though another question just occurred to me.

For pyrotechnics would it be possible to use Potassium peroxymonosulfate as an oxidizer? Wikipedia doesn`t list its decomposition temperature, while mentioning that is an oxidizer.

Possible Decomposition:
KHSO5 => KOH + SO2 + O2
This seems a bit unlikely but I am unsure of any other decomposition routes more likely.

Sorry if this question is ridiculous in some way, I checked nobody has mentioned this before.

It is a good question. I'm guessing peroxymonosulfate has approximately the same oxidising power as peroxydisulfate. A mixture of Ammonium peroxydisulfate and powdered aluminium (by my own experimentation) did not ignite easily but had a similar burn rate to very good potassium nitrate/sugar (and a lot hotter). Try and make the tetraamminecopper(II) salt (if you need help with this just email or U2U me). How pure is your peroxymonosulfate? Are you using "Oxone"?

[Edited on 18-7-2012 by RadioTrefoil]

Boron Trioxide - 18-7-2012 at 07:24

RadioTrefoil:

Excellent, I was hoping that potassium peroxymonosulfate would be as good as potassium nitrate, because in Canada nitrates are becoming hard to get, while I have seen lots of peroxymonosulfate available. I do not have any at the moment but I plan to get some soon, I haven't seen Oxone brand around but am sure I could find it.

Right now I have limited lab capability so I doubt I could make the tetraamminecopper(II) salt, though thanks for the advice.

plante1999 - 18-7-2012 at 07:30

Quote: Originally posted by Boron Trioxide

because in Canada nitrates are becoming hard to get.

You mean near impossible! Thats the reason why I bought a platinum anode for electrolysis, with this I can make oxidizer that I can use to dissolve copper or as general oxidizers in the lab. I'm not in energetic chemistry, but I suppose one could use them for pyrotechnics.

Chemistry Alchemist - 19-7-2012 at 09:34

What colour is Lead's tarnish? i was in K-mart today in the fishing section and saw a sinker pretty tarnished, but it was a rainbow colour, most sinkers are lead but some are made from Bismuth... would this sinker i saw the a bismuth sinker if it has a rainbow colour effect starting to form?

99chemicals - 19-7-2012 at 12:58

Quote: Originally posted by Chemistry Alchemist

What colour is Lead's tarnish? i was in K-mart today in the fishing section and saw a sinker pretty tarnished, but it was a rainbow colour, most sinkers are lead but some are made from Bismuth... would this sinker i saw the a bismuth sinker if it has a rainbow colour effect starting to form?

Yes the sinker is definitively bismuth. Bismuth has a very pretty oxide layer that can be many colors. The sinker in question should have been almost twice as expensive as lead too.

http://en.wikipedia.org/wiki/File:Bi-crystal.jpg

I am pretty sure that the thickness of the oxide is what affects the color

Sublimatus - 19-7-2012 at 13:01

Yeah, the color is mostly dependent on the thickness, based on my experience.

If you melt up some bismuth and skim off the oxidized skin on the top, you'll see a very silvery liquid reminiscent of mercury. Then just let it go, and you'll see a progression through a series of interference colors over the next couple of seconds until the oxide gets so thick that it's just a crusty matte gray.

Chemistry Alchemist - 19-7-2012 at 21:06

Is the sinker safe to melt in a pot?

Chemistry Alchemist - 19-7-2012 at 21:27

Also, is there ways to test if it is Bismuth with acids? Any acids dissolve lead but not bismuth... HCl for example?

99chemicals - 22-7-2012 at 07:31

Quote: Originally posted by Chemistry Alchemist

Is the sinker safe to melt in a pot?

Yes you can safely melt bismuth at home with out any worry of it being toxic. Gloves are highly recommended when working with molten bismuth. Even though it has a low melting point it still hurts like hell when it hits your skin.

As to your other question conc. nitric acid should dissolve bismuth with heating.

https://www.youtube.com/watch?v=xhokO4kzfuA

liquidlightning - 22-7-2012 at 21:08

Can you heat glassware in a microwave oven? (obviously not one that will ever again be used for food)

Boron Trioxide - 22-7-2012 at 22:26

Could someone please tell me what I am doing wrong with my chlorate cell?

I am using a large carbon anode, that when using a current density of 35 mA per cm2 can be run at 1.7 amps, so I ran it at this amperage for 3 hours in potassium chloride, with a stainless steel spoon as my cathode. No chlorate was produced, only a small amount of iron hydroxide. So I switched the spoon for a tube of chrome, this also didn't work at all.

The final reaction mixture smelled slightly of chlorine, a very slight yellow with a pH of 9-10.

Did I just not run it long enough or is 1.7 amps too low to produce chlorates after any amount of time?

plante1999 - 23-7-2012 at 02:19

Go on my website and download the chlorate guide pdf.

In the small scale electrosynthesis of it you will find the info you need.

http://hclo3chem.weebly.com/pdf.html

Hop this helped you, and after the reading please respond to the poll on the pdf tab.

99chemicals - 23-7-2012 at 03:50

Quote: Originally posted by liquidlightning

Can you heat glassware in a microwave oven? (obviously not one that will ever again be used for food)

I have done that several times. As far as I know it is safe. If you are doing that use a beaker or a thin walled piece of glass.

Don't use thick glass(like votive candle holders) as there is a higher likelihood that it will crack.

zoombafu - 28-7-2012 at 17:48

Does anyone know where an individual can get suba seals (rubber septa) ? Ive been looking on ebay for a while as well as various other hobby chemistry sites and can't find them.

mnick12 - 28-7-2012 at 21:53

IIRC they quite available, http://www.ebay.com/sch/i.html?_nkw=rubber+septum&_sacat...

Which ebay were you looking at?

zoombafu - 28-7-2012 at 22:37

Quote: Originally posted by mnick12

IIRC they quite available, http://www.ebay.com/sch/i.html?_nkw=rubber+septum&_sacat...

Which ebay were you looking at?

Well hot damn, I must be suffering from a mental deficiency and smoking dope and hitting my head with a hammer wile sniffing glue. Thanks

Lambda-Eyde - 29-7-2012 at 07:40

Laboy glass also has rubber septa, as well as cannulae and needles.

liquidlightning - 2-8-2012 at 01:18

How well do retorts work for distilling liquids? Would it be feasible to distill about about 500ml hydrochloric acid (not including added water to dilute to 20%) in a few hours with one, or do you have to distill ultra slow due to the air cooled condenser?

[Edited on 2-8-2012 by liquidlightning]

[Edited on 2-8-2012 by liquidlightning]

solo - 2-8-2012 at 09:00

C6H5CH2CH(CHNH2)CH3.....not sure what this is called, my guess would be 2-dimethylamine-1- phenylpropane.... Solo

manimal - 3-8-2012 at 18:51

My question has to do with 37% formalin inhibited with methanol. How difficult would it to be to remove this methanol to prevent side reactions, e.g. by heating on a water bath? How much of the methanol exists in equilibrium as methylal, and would boiling this off result in a substantial loss of formaldehyde?

DJF90 - 6-8-2012 at 10:39

I've personally rotavapped some formalin to the point that it becomes much more viscous and begins to cloud. It's poured out on a hard surface in a thin layer (read: pyrex baking dish) and as it cools it solidifies. Scraping this solid into flakes or "shavings" will allow proper desiccation over anhydrous calcium chloride. The solid is removed and ground in a pestle and mortar before being returned to the desicator. The fine, dry powder that is obtained is paraformaldehyde, (CH2O)n.

solo - 8-8-2012 at 19:50

....the hydrolysis of phenylacetamide will produce PAA, and a by product of an amine.... will the amine be methylamine?or ammonium chloride if hydrolysed with HCL or ammonium sulfate if hydrolysed with sulfuric acid? .. once the phenylacetamide has been put into solution in methanol and a strong solution of an acid or a base is added and refluxed for three hours...... does anyone have first hand notes on the hydrolysis, ....bits and pices of the info was gathered at organic synthesis and reading Marchs 6th edition .....solo

[Edited on 9-8-2012 by solo]

manimal - 11-8-2012 at 19:06

Quote: Originally posted by DJF90

I've personally rotavapped some formalin to the point that it becomes much more viscous and begins to cloud. It's poured out on a hard surface in a thin layer (read: pyrex baking dish) and as it cools it solidifies. Scraping this solid into flakes or "shavings" will allow proper desiccation over anhydrous calcium chloride. The solid is removed and ground in a pestle and mortar before being returned to the desicator. The fine, dry powder that is obtained is paraformaldehyde, (CH2O)n.

Interesting, so do you mean to say that the CH2O would "rather" polymerize than evaporate?

solo - 13-8-2012 at 09:37

Will the Bucherer reaction displace a hydroxy by an amino group in an alkyl.....?..or only on a benzene ring?..solo

Nicodem - 13-8-2012 at 10:24

Quote: Originally posted by solo

Will the Bucherer reaction displace a hydroxy by an amino group in an alkyl.....?..or only on a benzene ring?..solo

The mechanism is depicted on the Wikipedia entry for Bucherer reaction. You can now answer your own question.
Also, the scope of this reaction does not expand to just any phenol. It has to be a phenolic compound that has a substantial equilibrium for the reverse enolization.

solo - 14-8-2012 at 08:35

Nicodem.....thanks for the reply, I had read,

"Replacement of hydroxy by amino groups occurs in the Bucherer reaction; the reagent is an aqueous solution of bisulfite and ammonia or an amine, and the hydroxy groups of naphthols or resorcinol are most easily replaced. The Bucherer reaction occurs via the keto tautomers of the phenols (163), and is not to be classed as aromatic substitution.
The 4-hydroxy group in 2,4-dihydroxyquinoline may be replaced by amines; hydrochloric acid aids the reaction with aniline (138). Aminolysis of an o-nitro- phenol has been reported, but the reaction is more difficult than that of the corresponding nitrophenyl alkyl ethers (540). Here again it might be argued that these direct replacements of hydroxy groups are in reality condensations of the keto tautomers of the phenols."

......source,

Aromatic Nucleophilic Substitution Reactions- Bunnett and Zahler

http://filecloud.io/nd8lh7eo

Ref.163-DRAKEO: Organic Reactions, Vol. I, p. 105. John Wiley and Sons, Inc., New York (1942).....this is located in the SM library

.....but i guess wanted for it to work on an alkyl chain....hence, my stubborn question...which is now answered ....thanks....solo

[Edited on 14-8-2012 by solo]

Hexavalent - 1-9-2012 at 14:13

The preparation of tetramine copper (II) sulfate is usually carried out with concentrated ammonia solution.

Can it be done by using household ammonia, with the quantities adjusted accordingly?

plante1999 - 1-9-2012 at 14:33

Quote: Originally posted by Hexavalent

The preparation of tetramine copper (II) sulfate is usually carried out with concentrated ammonia solution.

Can it be done by using household ammonia, with the quantities adjusted accordingly?

Yes but if you want crystals of the tetramine copper II sulphate of it You will find 28% ammonia more suitable.

Hexavalent - 2-9-2012 at 04:36

Why? Is it just because there will be less water present with the concentrated ammonia? My plan was just to add enough ammonia solution to aqueous copper sulfate to form copper hydroxide and then to complex the precipitate again, before adding ethanol to precipitate out the tetramine copper sulfate.

ChemistryGhost - 9-9-2012 at 03:33

Can N-ethylhydroxylamine react with methyllithium to produce ethylmethylamine. if it works, then ethyllithium could be used for diethylamine(ethylethylamine) and propyllithuim could be used for ethylpropylamine. Will it work?

[Edited on 9-9-2012 by ChemistryGhost]

Endimion17 - 9-9-2012 at 05:43

Would liquid sulphur, heated a bit above its melting point (~115 °C), attack food grade silicone polymer? Would vulcanization occur and affect it? I have an idea, but I'm not willing to do any experiments yet.

gnitseretni - 10-9-2012 at 19:45

A couple of years ago I tried some hydroforming with my pressure washer but it didn't have enough pressure. It says 1800 PSI on it, but it's old so I'm sure it's less than that. Anyone know of a cheap and readily available pump (automotive maybe?) that can get to pressures of say 2500 PSI and higher? If I can find the right pump I'd like to give this another try. I'm trying to form 4" diameter 1.6mm thick copper circles into a conical cavity. Considering how incredibly soft copper is in it's annealed state, I thought my pressure washer would be plenty adequate. I thought wrong

watson.fawkes - 11-9-2012 at 05:32

Quote: Originally posted by Endimion17

Would liquid sulphur, heated a bit above its melting point (~115 °C), attack food grade silicone polymer? Would vulcanization occur and affect it? I have an idea, but I'm not willing to do any experiments yet.

The experiment to do is to immerse some samples of the silicone you want to use in liquid sulfur and pull them out an periodic intervals. Wash in toluene to clean them. Examine, with a magnifier if needed.

I would imagine that you'll get an attack. What I don't know is the degradation rate. I've not done the experiment, but I imagine you'll get liberation of H₂S and dehydrogenation of the polymer.

Endimion17 - 11-9-2012 at 05:58

Quote: Originally posted by watson.fawkes

Quote: Originally posted by Endimion17

Thanks. I've got only one piece of it and I don't want to spend money on this experiment. Plus I don't have the opportunity to do it soon...

crazyboy - 11-9-2012 at 15:48

Can 4A molecular sieves be used to remove water vapor from H2 gas? Sigma says 3A is suited to this purpose but I only have 4A. Do molecular sieves even absorb enough water to make them viable for drying H2 mixed with steam or would I just be better off passing the hydrogen over sodium sulfate or a similar chemical dessicant?

bbartlog - 11-9-2012 at 17:45

Quote: Originally posted by gnitseretni

A couple of years ago I tried some hydroforming with my pressure washer but it didn't have enough pressure. It says 1800 PSI on it, but it's old so I'm sure it's less than that. Anyone know of a cheap and readily available pump (automotive maybe?) that can get to pressures of say 2500 PSI and higher? If I can find the right pump I'd like to give this another try. I'm trying to form 4" diameter 1.6mm thick copper circles into a conical cavity. Considering how incredibly soft copper is in it's annealed state, I thought my pressure washer would be plenty adequate. I thought wrong

Seems like you'd need a hydraulic pump of some sort, and they don't really come cheap. Even a hand-operated pump (which would be OK for your purpose since you don't need any significant flow) sells for over $100.

gnitseretni - 11-9-2012 at 18:03

Ha, I just bought a hand operated pump for $70 five mins ago. Goes up to 9700 PSI. Should be enough

mineralman - 16-9-2012 at 10:11

I can't find any answer and hope it's new.

Can the ice build up from a freezer be classed as "UNCONVENTIONAL" distilled water when melted? mm

mineralman - 16-9-2012 at 10:22

Quote: Originally posted by gnitseretni

You can get vac pressure flow connections for air compressors, there may be one for water aplications. Add a water cooling system to aid in getting higher pressure's. maybe the pressure washer you already have can get you there. just a thaught. MM

Dr.Bob - 25-9-2012 at 06:52

Quote: Originally posted by crazyboy

Can 4A molecular sieves be used to remove water vapor from H2 gas? Sigma says 3A is suited to this purpose but I only have 4A. Do molecular sieves even absorb enough water to make them viable for drying H2 mixed with steam or would I just be better off passing the hydrogen over sodium sulfate or a similar chemical dessicant?

4A MS will absorb water, if they are well activated (usually bought that way, but if old, they can be heated under vacuum to dry them.) You could also use a chemical desicant like NaSO4, although it is slow to absorb, but it will be OK if there is a lot of H2O. But these types of drying agents can only do so much, so fast, so the H2 needs to be relatively dry when it starts to have them dry it well. If you have very wet H2, it may take several drying steps/towers to dry it well. But even H2 generated from water hydrolysis can be dried sufficiently with a drying column or two, under most cases. We have used hydrolysis H2 generators for H2 in the lab, and they worked fine.

watson.fawkes - 25-9-2012 at 07:20

Quote: Originally posted by Dr.Bob

But even H2 generated from water hydrolysis can be dried sufficiently with a drying column or two

A bubbler through concentrated sulfuric acid seems to be the standard first element in any drying train for gases generated from aqueous solutions. It will eventually dilute, of course, and lose its drying power.

Also, the reference I have on hydrogen brazing recommends 5A sieves for taking water vapor from tank hydrogen. My guess is that the adsorption rate may be a bit higher that with 4A.

making sodium fluoride

tetrahedron - 2-10-2012 at 05:06

can calcium fluoride be converted to sodium fluoride by boiling with soda, akin to the method starting with barium sulfate?

http://www.sciencemadness.org/talk/viewthread.php?tid=9123

CaF2 is even more soluble than BaSO4..

Panache - 6-10-2012 at 00:17

Quote: Originally posted by solo

....the hydrolysis of phenylacetamide will produce PAA, and a by product of an amine.... will the amine be methylamine?or ammonium chloride if hydrolysed with HCL or ammonium sulfate if hydrolysed with sulfuric acid? .. once the phenylacetamide has been put into solution in methanol and a strong solution of an acid or a base is added and refluxed for three hours...... does anyone have first hand notes on the hydrolysis, ....bits and pices of the info was gathered at organic synthesis and reading Marchs 6th edition .....solo

[Edited on 9-8-2012 by solo]

Vogel 3rd ed uses 30% caustic refluxed for 30 mins, reaction followed via NH3 coming off (ie past the condenser), when this ceases then finished. Also same edition uses refluxing HCl, reaction completed when solution loses turbidity.
if you have time i suggest just leaving it in 30%hcl for a week.

Hexavalent - 15-10-2012 at 12:23

If I prepare methyl benzoate with methanol and benzoic acid I will get that great fruity smell that we all know and love, but, if I prepare benzyl methanoate, i.e. with benzyl alcohol and methanoic acid (formic acid), will it still have the same smell?

UnintentionalChaos - 15-10-2012 at 12:26

Quote: Originally posted by Hexavalent

If I prepare methyl benzoate with methanol and benzoic acid I will get that great fruity smell that we all know and love, but, if I prepare benzyl methanoate, i.e. with benzyl alcohol and methanoic acid (formic acid), will it still have the same smell?

Why would it...the molecule is a different shape.

Hexavalent - 15-10-2012 at 12:41

That was what I thought...although I wasn't sure as the aromatic ring and aliphatic substituent were in the same 'place'.

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