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[*] posted on 10-1-2012 at 11:52


What is standard enthalpy of formation acetic acid,ammonium bicarbonate,ammonium acetate?
I want to calculate enthalpy of this reaction

NH4HCO3 + CH3COOH = CH3COONH4 + CO2 + H2O
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[*] posted on 13-1-2012 at 05:53
Oxygen balance


http://en.wikipedia.org/wiki/Oxygen_balance

Here is oxygen balance calculation accord. to Wikipedia. I have a problem to understand one thing:

Quote:
M = number of atoms of metal (metallic oxide produced).


Is it number of metal atoms or the number of oxide molecules produced?

EDIT: Found out, that the formula is bad (as I expected).
I looked at German Wikipedia and there is the correct formula (I hope), but unfortunately I don't understand it. :X

[Edited on 13-1-2012 by Adas]




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[*] posted on 16-1-2012 at 09:15


Is this possible?

KNO<sub>3</sub> + 2 NH<sub>3</sub> ----> KN<sub>3</sub> + 3 H<sub>2</sub>O




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[*] posted on 4-2-2012 at 09:01


Quote: Originally posted by Adas  
Is this possible?

KNO<sub>3</sub> + 2 NH<sub>3</sub> ----> KN<sub>3</sub> + 3 H<sub>2</sub>O


I don't know but if you're only trying to get the KNO<sub>3</sub> you could do this; 2 K + 2 NH<sub>3</sub> -> 2 KNH<sub>2</sub> + H<sub>2</sub>

2 KNH<sub>2</sub> + N<sub>2</sub>O →-> KN<sub>3</sub> + KOH + NH<sub>3</sub>
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[*] posted on 4-2-2012 at 10:39


Mostly theoretical, a little pondering, but might a poly furfuryl alcohol resin have similar hypergolic reactions as the monomer with nitric acid/derivatives? What sort of science is involved in hypergolic reactions?
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[*] posted on 4-2-2012 at 14:00


Quote: Originally posted by Adas  
Is this possible?

KNO<sub>3</sub> + 2 NH<sub>3</sub> ----> KN<sub>3</sub> + 3 H<sub>2</sub>O
No. Are you one of those people who thinks that any equation that can be balanced is possible? I sure hope not.
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[*] posted on 4-2-2012 at 16:45


Quote: Originally posted by entropy51  
Are you one of those people who thinks that any equation that can be balanced is possible? I sure hope not.
He forgot to write it with the proper reaction conditions:
KNO<sub>3</sub> + 2 NH<sub>3</sub> ----<sup>magic</sup>----> KN<sub>3</sub> + 3 H<sub>2</sub>O
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[*] posted on 4-2-2012 at 16:50


Quote: Originally posted by watson.fawkes  
[KNO<sub>3</sub> + 2 NH<sub>3</sub> ----<sup>magic</sup>----> KN<sub>3</sub> + 3 H<sub>2</sub>O
Have you noticed that we have had a huge influx of wizards recently? The amount of magic is absolutely breathtaking!
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[*] posted on 8-2-2012 at 16:31


"Preparation of Ethylenediammonium diacetate (EDDA)
A 150 ml beaker, containing 100 ml dry ether and 12.0 g (0.2 mol) of ethylenediamine, is placed in an ice-bath and a solution of 24.0 g (0.4 mol) glacial acetic acid in 20 ml ether is added with stirring at such a rate as to prevent boiling of the ether. The solution is left to crystallize overnight, then filtered with suction, the crystals washed with ether and recrystallized from approximately 50 ml MeOH. Yield after drying in a vacuum desiccator is around 27.5g (75%) of colorless needles, mp 114°C."


......source,

http://www.erowid.org/archive/rhodium/chemistry/edda.html


......i've tried this process to the letter and the product has a low MP 75 C.....any idea why the material turns pasty while the addition of the ether/GAA, even though i have it stirring.....maybe the magnetic stirrer isn't sufficient and need to use overhead stirrer....any thoughts, from someone familiar with the synthesis?.......solo




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[*] posted on 8-2-2012 at 16:43


I found this over at Hyperlab, it may provide the answer......

Practical test methods for the synthesis
ethylenediamine (etilendiammoniya) diacetate.

Some time ago, someone won a
of 50% ethylenediamine grade B, dostatogo for free.
But from it we can make a useful substance, he thought.
And, indeed, the substance is called ethylene diamine diacetate
used as a mild and efficient
catalyst for the condensation reatsy various aldehydes
and nitroalkanes. Otherwise known as Henry reaction (Henry reaction).

The first source was the synthesis of the recipe with a friend of his L.Tittse T.Ayherom.
It was decided to do what they recommend. But it was nevertheless
viewed
Alternatively, the site of synthesis of rhodium. But a glance at and
noting that the mass of the reagents used are the same here and there, completely
transfer method did not. And in vain ...

L.Tittse, T.Ayher
"Physical Organic Chemistry," page 468
http://chemister.da.ru/Books/Chembooks/Pra...ikum/Titce.djvu

P-3a Etilendiammoniya diacetate.

CH3COOHH2N-CH2-CH2-NH2 ---------> H3N-CH2-CH2-NH3 * 2CH3COO-60.1 60.1 180.2
Reaction. The formation of ammonium salts of the free amine and acid.
Etilendiammoniya diacetate is a gentle and effective
catalyst for the interaction of CH-acidic compounds
with carbonyl groups (pH 7 in water).

To a solution of 12.0 g (0.20 mol) of ethylenediamine in 100 ml of anhydrous
ether was added dropwise with stirring 24.0 g (0.4 mol) of acetic
acid in 20 ml of ether, and then left for 14 hours in the refrigerator.

The precipitated crystals were filtered, washed with ether and
recrystallized from 50 ml of MeOH, to give 19.8 g (83%) of salt
as colorless crystals, mp. 114 ° C


I must say that this recipe, at least one typo:
not "give 19.8 g (83%) of salt," and "receiving 29.8 g (82.7%) of salt."
And a lack of understanding: to cool the mixture in an ice bath
the addition of acidñ.


https://www.rhodium.ws/chemistry/edda.html
Preparation of Ethylenediammonium diacetate (EDDA)

A 150 ml beaker, containing 100 ml dry ether and 12.0 g (0.2 mol)
of ethylenediamine, is placed in an ice-bath and a solution of 24.0 g (0.4 mol)
glacial acetic acid in 20 ml ether is added with stirring at such a rate as to
prevent boiling of the ether. The solution is left to crystallize vernight,
then filtered with suction, the crystals washed with ether and recrystallized
from approximately 50 ml MeOH. Yield after drying in a vacuum desiccator is
around 27.5g (75%) of colorless needles, mp 114 ° C.


In 150 ml glass of the chemical placed in an ice bath containing
100 ml of dry ether and 12.0 g (0.2 mol) of ethylenediamine was added at
stirred solution of 24.0 g (0.4 mol) of glacial acetic acid in 20 ml
ether
at such a rate as to prevent boiling of the ether. The solution was allowed to stand
night
for crystallization and then filtered with suction. The crystals were washed
ether and recrystallized from approximately 50 ml of methyl
alcohol.
The yield, after drying in a vacuum desiccator, is about 27.5 g (75%)
colorless crystalline needles with a melting point of 114 ° C


In this recipe the volume of the cup is completely filled with a mixture
which is inconvenient. Shed easily.

Description of the synthesis.
In a 250 mL conical flask with a wide mouth (29) was weighed clean
ethylenediamine in an amount of 12.0 g (0.2 mol) and mixed with 100 ml
dehydrated
ether (dried calcined alumina produced, about 10 g per 100
ml)
In another small flask weighed 24.0 g (0.4 mol) of glacial
acetic acid and diluted with 20 mL of ether.
With the help of a pipette 10 ml acid solution in ether was added slowly
to a solution of the amine and the mixture shaken.
The reaction is exothermic, stand a pair of white.

Since the synthesis was planned for the recipe and L.Tittse T.Ayhera, the cooling
reatsionnoy mixture did not care, so the flask was cooled from time to time
in the freezer without giving the airwaves to a rolling boil.

Almost immediately after the addition of the first portions of acid, a white
tight
precipitate, which was stirred and loosened with a glass rod.
After the addition of acetic acid formed a rich, white,
crystalline precipitate, like powdered sugar. But in some places
fused in clumps, as well as adhering to the walls of the flask.
All this mess scraped from the walls and crush glass
stick.

Using this method a conical flask Eylenmeyera optimally
as
work with such a deposit in the round (flat) bottom is very inconvenient. A Chem.
glass
plug does not shut up. For those who like to work glasses, it is better to take
amount of not less than 250 ml. Since the 150 ml beaker chemistry, the recommended
Website Rodia simply too small for normal operation.

Following the procedure, the bulb with the precipitate in ether was left overnight in
the refrigerator.
The next day, visually, the precipitate in the flask is not increased. Therefore, the
the need for long standing in the cold on the issue.

Remembering all the essential gemmoroynost vacuum filtration solutions
it was decided to abandon it. A carefully and completely drain the air with
precipitate and wash it several times with ether in portions of 50 ml.

Further, in the same vessel, the precipitate was dried at 50-60 degrees in the oven to
complete dryness, stirring occasionally, and eventually became similar to
baby food.

Recrystallization was carried out from methyl alcohol, a gradual
its addition to the powder in a water bath. Results for the full
dissolution of the precipitate, it took 45 ml of alcohol.

The hot clear solution was poured in a dish on which is in
hot
water, and then, with this water is cooled slowly, periodically
stirring.
After some time, drop a small, colorless, transparent
crystals.
For a more complete separation of crystals placed a cup in the refrigerator for
a few hours. After that, the mother liquor was drained and the crystals rapidly
pressed on the cooled glass filter.

The resulting product was dried in a desiccator under vacuum at first, after standing
in sulfuric acid until the weight change.

The yield is 28.3 g (78%) of transparent yellowish crystals
with a melting point of about 113 ° C
Subsequently, while cooling the mother liquor in the freezer, dropped
about 4 grams of crystals.

Drying of ethylenediamine.
Ethylenediamine (1,2-diaminoethane) H2N-CH2-CH2-NH2
Mol. weight of 60.100 - a colorless liquid with ammonia odor;
mp. 8,5 ° C, bp. 117,0 ° C; 62,5 ° C (100 mm Hg. Art.)
Miscible with water, alcohol, acetone, benzene, ether;
poorly soluble in n-heptane.
Forms azeotropic mixtures with water: hydrate, ethylenediamine C2H8N2 * H20
mp. 11 ° C, bp. 118,5 ° C;
with toluene, bp. 103 ° C, 30% ethylenediamine
a cellosolve, bp. 130 ° C, 31-32% ethylene diamine
(Brief Chemical Encyclopedia)

As already mentioned, in the presence of 50% of the present solution and the reaction
required anhydrous ethylenediamine.

On the advice of friends (Angel, respect!) Was employed method
salting out.
After trying on a small amount of amine this method, and making sure it
applicability, it was decided to move it to the big boot.

300 g of the amine solution are placed in half-liter bottle of chemicals.
Chem dishes like funnel, etc. it was a pity,
because of the ravages of hot conc. alkali.

The solution was shaken with small amounts of alkali NaOH
(Noticeably 30-40 g) to form a saturated alkaline
solution, followed by standing and separation of the layers.
After that, the bottom layer of liquor pulled the 20 cc syringe.
After the third division of NaOH no longer dissolved, and it was
decided to heat the mixture on a water bath, repeating the same procedure.
It was a success, and it should be noted, when heated
salting out and separation of the layers is much faster.

Thus, the last portion of the total alkali, 200 grams
load does not dissolve completely even after long heating,
about two hours, and periodic shaking.

Shit! No need to use the bottle rocket.
Female cracked right in the bath! Well, not that the bottom has dropped out, and
amine failed to save. It is necessary to use a heat-resistant container.

When he came to the conclusion that a good idea, to begin to overtake on the recommended
method,
azeotrope with the garbage, it was decided to clarify the boiling point of substances.

And what is revealed:

Ethylenediamine bp. 117.0
Ethylenediamine hydrate, bp. 118.5 (760 mm)

It's fucking reverse azeotrope, so even with minimal
temperature difference.

With the help of a thermometer available, hardly will be fixed
such a small difference.

Therefore, the distillation has been postponed until further and decided to
drier according to the method recommended by Katznelson.
That is, drying in a closed bank on fused alkali at 100 degrees
throughout, though, would be 10-12 hours of oven.
And then drive away the amine, discarding the first and last fractions.

That was done. After drying, alkali cakes have hardly changed
and fun rolled into an anime. This indicates that the water in it
is almost gone. Ethylenediamine distilled into three unequal parts, for
synthesis was used the average (the largest) fraction.




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[*] posted on 21-2-2012 at 10:10


Can anyone explain me the amalgamation process? I understand it activates metals and removes oxide coating. But what happens to Hg or mercury salts? A short example with sodium or aluminium would help alot, because im curious about this process. Thank you.
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[*] posted on 21-2-2012 at 12:40


What is the actual reaction between dihydroxyacetone and ammonia?
I have tried searching for the answer online, and apparently the reaction is very complicated.

One source suggests that pyrazine derivitives form.
http://onlinelibrary.wiley.com/doi/10.1002/1097-0010(200006)80:8%3C1262::AID-JSFA634%3E3.0.CO;2-T/full

I also know that bromoacetone reacts with NH3 to make 3,6-dimethyl-2,4-dihydropyrazine, C6H10N2.

[Edited on 21-2-2012 by AndersHoveland]
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[*] posted on 25-2-2012 at 14:49


Does Magnesium chlorate is solube in methanol? I want to synthesise it from KClO3 and MgSO4, I thinked to boil a mixture of KClO3 and MgSO4 in methanol but I dont know if Magnesium chlorate is solube in Methanol.


Thanks!!!




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[*] posted on 2-3-2012 at 18:34


If I mix a solution of sodium carbonate (containing three equivalents of sodium ions) with one equivalent of phosphoric acid, and heat the resulting solution, what is the result? Does all the carbonate eventually get driven off as CO2, yielding a basic solution of Na3PO4? Or does some CO2 get held in solution by the rather basic Na3PO4?



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[*] posted on 4-3-2012 at 20:08


Hi,

What is the correct stopper size for a flask of dimension 24/40?
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[*] posted on 5-3-2012 at 05:58


Hello

What will be the product from reaction between primary amine and grignard reagent?
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[*] posted on 5-3-2012 at 13:14


Is it possible to isolate tetramethylammonium methoxide?
Is this compound a liquid?

If it is a liquid, I am sure it would be a very dangerously corrossive substance, much more caustic than sodium hydroxide.
Could this have application for dissolving certain metals that are resistant to acid?
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[*] posted on 6-3-2012 at 17:53


Quote: Originally posted by manimal  
Hi,

What is the correct stopper size for a flask of dimension 24/40?


I believe a #4 stopper should work reasonably well for a 24/40 female glass joint.




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[*] posted on 6-3-2012 at 18:05


Quote: Originally posted by plante1999  
Does Magnesium chlorate is solube in methanol? I want to synthesise it from KClO3 and MgSO4, I thinked to boil a mixture of KClO3 and MgSO4 in methanol but I dont know if Magnesium chlorate is solube in Methanol.
Thanks!!!


Old references say magnesium chlorate is soluble in alcohol (also acetone). Potassium chlorate on the other hand really isn't, much... likewise MgSO4 is only sparingly soluble. Sounds like it would be a better way to get to KClO3 from MgClO3 than the other way around.




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[*] posted on 6-3-2012 at 18:19


Quote: Originally posted by bbartlog  
Quote: Originally posted by plante1999  
Does Magnesium chlorate is solube in methanol? I want to synthesise it from KClO3 and MgSO4, I thinked to boil a mixture of KClO3 and MgSO4 in methanol but I dont know if Magnesium chlorate is solube in Methanol.
Thanks!!!


Old references say magnesium chlorate is soluble in alcohol (also acetone). Potassium chlorate on the other hand really isn't, much... likewise MgSO4 is only sparingly soluble. Sounds like it would be a better way to get to KClO3 from MgClO3 than the other way around.


Thanks! In fact I think the reaction is favorable since one of the product is soluble and the two reactant are sparingly solube.




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[*] posted on 9-3-2012 at 08:04


Is white phosphorus soluble in ethanol? I need that info ASAP, and don't have the time to search for it. Thanks.
(I'm not experimenting with it, just writing an article)




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[*] posted on 9-3-2012 at 08:29


Yes.
<a href="http://books.google.com/books?id=CXinC8gW6BEC&pg=PA334&lpg=PA334&dq=white+phosphorus+solubility+table+ethanol&source=bl&ots= XrOCfOcEPY&sig=pZnmlMvlEnSzLw0mB9ZcsSo_kx4&hl=en&sa=X&ei=VS9aT8_qAuHY0QGTvoCtDw&ved=0CFAQ6AEwBg#v=onepage&q&f=false">Re ference</a>
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[*] posted on 9-3-2012 at 09:02


Thanks! I supposed it was, though much less than in carbon disulphide. If you happen to stumble upon an exact value, I'll appreciate it.



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[*] posted on 20-3-2012 at 10:45


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 -.-
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[*] posted on 20-3-2012 at 10:53


Quote: Originally posted by benzeentje  
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?




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