Author Topic: Short Questions Thread (Read 10825 times)

overunity33 · « **Reply #780 on:** April 04, 2011, 11:52:28 PM »

pretty damn soluble dont have a number sorry

Wizard X · « **Reply #781 on:** April 05, 2011, 12:41:08 AM »

Quote from: Tungsten. on April 04, 2011, 09:12:07 PM

Anybody know the solubility of lysergic acid in ethanol?

http://www.jbc.org/content/106/1/393.full.pdf

Tungsten. · « **Reply #782 on:** April 05, 2011, 01:25:35 AM »

Thanks

2bfrank · « **Reply #783 on:** April 09, 2011, 03:36:17 AM »

http://wn.com/BROMINE_and_ALUMINUM_reaction

see AlCl3 prep. Just thought it interesting, and wondered if anyone has played with this before???

2bfrank · « **Reply #784 on:** April 09, 2011, 09:06:09 AM »

if no one has,well that wont be for long. This looks very interesting indeed. Like dry ice/ acetone, aint hard at all. Could be a good way to get such a lewis acid such as AlCl3. FC, here we go.

atara · « **Reply #785 on:** April 10, 2011, 01:53:18 AM »

Video doesn't display for me. What's the gist?

All I can say is that if it involves elemental chlorine it's going to be out of the question for a lot of people.

nk40ouvm · « **Reply #786 on:** April 10, 2011, 01:54:50 AM »

Quote from: ziggy on April 09, 2011, 03:36:17 AM

http://wn.com/BROMINE_and_ALUMINUM_reaction

see AlCl3 prep. Just thought it interesting, and wondered if anyone has played with this before???

I have played with this. IMO bromine is easier to measure and work with, and the reaction with aluminum goes quickly without external heat. Much better than hot tubes with HCl or Cl2. Main disadvantage for home chemists is that suitable bromine containing compounds are slightly harder to find, but most should be able to find bromides or BCDMH OTC, and both are suitable for making bromine. The higher cost of bromine compounds is more than compensated by greater convenience.

It is possible to rapidly and easily make anhydrous AlBr3 on semi-technical scale in the lab, with distillation of product driven by the heat of reaction itself. See http://pubs.acs.org/doi/abs/10.1021/ie50366a023.

I believe that aluminum electrical wire would be a good source of aluminum for preparing AlBr3 or other aluminum halides, since it contains less alloying elements than household foil or structural aluminum. It is available in USA as heavy "service entrance wire" at your local big box home store.

2bfrank · « **Reply #787 on:** April 10, 2011, 02:05:01 AM »

The link works fine for me atara, I just repeated it twice, the AlCl3 is one of the experiments - which also worked fine. Sorry about that though. I did check it but., Yes I see the AlBr3 perhaps more accesible, but I liked the look of the AlCl3 prep, It will be abit of fun, and see what I get. Ill have to look into the BCDMH, as its here where I am. I am sure I have read that it is indeed a good source. So thanks for that info and the link.

2bfrank · « **Reply #788 on:** April 10, 2011, 02:12:35 AM »

Anhydrous Aluminum bromide as per link about

psychexplorer · « **Reply #789 on:** April 10, 2011, 03:00:30 AM »

Quote from: nk40ouvm on April 10, 2011, 01:54:50 AM

Quote from: ziggy on April 09, 2011, 03:36:17 AM
http://wn.com/BROMINE_and_ALUMINUM_reaction

see AlCl3 prep. Just thought it interesting, and wondered if anyone has played with this before???

I have played with this. IMO bromine is easier to measure and work with, and the reaction with aluminum goes quickly without external heat. Much better than hot tubes with HCl or Cl2. Main disadvantage for home chemists is that suitable bromine containing compounds are slightly harder to find, but most should be able to find bromides or BCDMH OTC, and both are suitable for making bromine. The higher cost of bromine compounds is more than compensated by greater convenience.

It is possible to rapidly and easily make anhydrous AlBr3 on semi-technical scale in the lab, with distillation of product driven by the heat of reaction itself. See http://pubs.acs.org/doi/abs/10.1021/ie50366a023.

I believe that aluminum electrical wire would be a good source of aluminum for preparing AlBr3 or other aluminum halides, since it contains less alloying elements than household foil or structural aluminum. It is available in USA as heavy "service entrance wire" at your local big box home store.

Do you have a PDF of the reference?

2bfrank · « **Reply #790 on:** April 10, 2011, 03:54:58 AM »

I posted the pdf file above, or do you mean something else psychexplorer???

RoidRage · « **Reply #791 on:** April 11, 2011, 07:34:22 AM »

Stupid question, but I'm seriously not too sure if my numbers are correct considering I really don't remember too well how to calculate it ...Looks like I forget everything I see in school... $:-\$ Not too sure where my analytical chemistry textbook is right now, so If anybody remember how to do it on top of their head, you help would be appreciated

I've tried abacus's methanolic methylamine preparation from nitromethane (/hiveboard/methods/000382493.html) if somebody isn't familiar with the process)...I want to titrate the methanolic solution with Hcl, but I do not remember how to calculate the pH at the equivalence point when a weak base is titrated by a strong acid (It's not 7, like many write-ups erronously state more often than not

... It's under 7 for sure) ... Methylamine pKa is 10.62 ... If I remember correctly, calculating this the requires the Henderson–Hasselbalch equation (hxxp://en.wikipedia.org/wiki/Henderson%E2%80%93Hasselbalch_equation)... I seriously now really sucks at math... If I'm right, plugging the numbers in the equation, I would get that the ph equivalence point is at (14-10.62 = 3.38 ... Using the conjugated base pKb to resolve

) ... Is there anything wrong with my calculations ??

Thanks in advance, as always

akcom · « **Reply #792 on:** April 11, 2011, 08:38:17 PM »

You titrate a solution of MeNH2 until its neutral. Best wasy is to use a pH indicator. Once it's neutral, figure out how many moles of HCl you added and thats how many moles of methylamine you had in your solution

RoidRage · « **Reply #793 on:** April 11, 2011, 08:50:39 PM »

Titration isn't complete at neutral pH...When a weak base is titrated by a strong acid, titration is complete at pH < 7 ... Same thing apply for the opposite case (Titration is complete at > pH 7 though)...Reread what I wrote

Vesp · « **Reply #794 on:** April 11, 2011, 10:42:01 PM »

Would just using a weak acid with the weak base and than getting it to 7 be cheating?

Perhaps try this out? hxxp://www.changbioscience.com/calculator/HendersonHasselbach.html

Not sure if it works, I just googled "Henderson–Hasselbalch equation calculator" and clicked on the first thing I saw...

But I generally use those website calculators as a crutch and they do all right. I suck at math as well, but I think its mostly because I never apply when I know I can just go find a calculator out there designed specifically for what I need to do

Wizard X · « **Reply #795 on:** April 12, 2011, 12:04:58 AM »

Quote from: RoidRage on April 11, 2011, 08:50:39 PM

Titration isn't complete at neutral pH...When a weak base is titrated by a strong acid, titration is complete at pH < 7 ... Same thing apply for the opposite case (Titration is complete at > pH 7 though)...Reread what I wrote

Read this...

http://www.brynmawr.edu/Acads/Chem/Chem104lc/study/buffer6.html same calculations as with methylamine.
Also read attachment.

Buffering a methylamine solution.
http://www.brynmawr.edu/Acads/Chem/Chem104lc/study/buffer5.html
http://www.brynmawr.edu/Acads/Chem/Chem104lc/study/buffer2.html

RoidRage · « **Reply #796 on:** April 12, 2011, 12:40:03 AM »

Thanks Wizard X and Vesp, your help is appreciated!

psychexplorer · « **Reply #797 on:** April 12, 2011, 03:45:47 AM »

Quote from: ziggy on April 10, 2011, 03:54:58 AM

I posted the pdf file above, or do you mean something else psychexplorer???

Um, I'm not sure how I missed that...right above, too.

Probably has something to do with a little accident. I mistakenly dropped all my NAAA into an uncovered container of o-toluidine. Clumsy me.

akcom · « **Reply #798 on:** April 12, 2011, 04:33:24 AM »

RoidRage, how embarrassing. Seems I've forgotten a lot since chem 2. sorry about that

RoidRage · « **Reply #799 on:** April 13, 2011, 07:45:58 AM »

Quote from: akcom on April 12, 2011, 04:33:24 AM

RoidRage, how embarrassing. Seems I've forgotten a lot since chem 2. sorry about that

Don't worry...I had to ask because I forgot too

Seriously, I never though I would use that in my life

Author Topic: Short Questions Thread (Read 10825 times)

overunity33

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Wizard X

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Tungsten.

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2bfrank

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2bfrank

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atara

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nk40ouvm

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2bfrank

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psychexplorer

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2bfrank

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RoidRage

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akcom

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Vesp

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Wizard X

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RoidRage

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psychexplorer

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akcom

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