January 27, 2021, 05:13:51 AM
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21
Organic Chemistry Forum / Re: Carvone and tartaric acid
« Last post by sharbeldam on Yesterday at 11:58:01 AM »
Can someone just give me a reaction that I can do on carvone that once I react it with tartaric acid it gives two diastereomers? I’m so confused now
22
Organic Chemistry Forum / Re: Making glacial acetic acid
« Last post by billnotgatez on Yesterday at 11:05:02 AM »
Sometimes I wonder

I look up Azeotrope in WIKI and find this

https://en.wikipedia.org/wiki/Azeotrope#Zeotropy
Quote
Zeotropy[edit]
Combinations of solvents that do not form an azeotrope when mixed in any proportion are said to be zeotropic. Azeotropes are useful in separating zeotropic mixtures. An example is acetic acid and water, which do not form an azeotrope. Despite this, it is very difficult to separate pure acetic acid (boiling point: 118.1 °C) from a solution of acetic acid and water by distillation alone. As progressive distillations produce solutions with less and less water, each further distillation becomes less effective at removing the remaining water. Distilling the solution to dry acetic acid is therefore economically impractical. But ethyl acetate forms an azeotrope with water that boils at 70.4 °C. By adding ethyl acetate as an entrainer, it is possible to distill away the azeotrope and leave nearly pure acetic acid as the residue.

I look up Zeotropy in WIKI
https://en.wikipedia.org/wiki/Zeotropic_mixture
and there is no mention of acetic acid

I look up Acetic acid in WIKI
https://en.wikipedia.org/wiki/Acetic_acid
and there is no mention of Zeotropy


As an aside
there is Azeotrope tables in WIKI
https://en.wikipedia.org/wiki/Azeotrope_tables
that lists
Quote
acetic acid 118.1C No azeotrope
23
Organic Chemistry Forum / Re: Making glacial acetic acid
« Last post by billnotgatez on Yesterday at 10:23:34 AM »
By the way from
https://www.wolframcloud.com/objects/demonstrations/SeparationOfAceticAcidFromWaterUsingEthylAcetateEntrainer-source.nb#:~:text=The%20binary%20mixture%20of%20acetic,of%20a%20severe%20tangent%20pinch.


The binary mixture of acetic acid and water does not form an azeotrope. Despite this, obtaining pure acetic acid (with boiling point 118.1 °C) from a solution of acetic acid and water by distillation is very difficult because of the presence of a severe tangent pinch.

24
Organic Chemistry Forum / Re: Making glacial acetic acid
« Last post by billnotgatez on Yesterday at 10:12:23 AM »
... separating it from water is tricky, since they're both matching azeotropes and not even fractional distillation will work out.

...(Im not that interested in getting a very pure batch, 50% or more is good enough for me).

This is confusing
What is the difference between azeotropes and a not pure batch
25
Organic Chemistry Forum / Re: Caffeine in energy drinks
« Last post by billnotgatez on Yesterday at 09:54:53 AM »
In this forum we have a rule that you participate in getting the answer to your question.
Often we point the new members to the resources on the internet like GOOGLE and WIKIPEDIA.
Wikipedia is a good starting point to find your initial understanding by providing insight into the topic.
The Wikipedia also has references at the bottom that can give you further good resources for your answer.
Once you have some understanding of your topic you can use Google to search.
Since you have insight from reading  Wikipedia, you will know the terminology to do the searches.

Try looking at this link
https://en.wikipedia.org/wiki/Caffeine
The whole article is very informative including the portion on synthesis
https://en.wikipedia.org/wiki/Caffeine#Synthesis
From there you can go on to other resources and read more.

If you still do not understand what you need to know please come back and we will try to help you learn the answer.

By the way from the forum rules
You have to show your attempts or thoughts at solving the question to receive help.
This is a forum policy.
Click on the link near the top center of the forum page.
Forum Rules: Read This Before Posting.
http://www.chemicalforums.com/index.php?topic=65859.0


26
Organic Chemistry Forum / Making glacial acetic acid
« Last post by Limon on Yesterday at 09:28:02 AM »
Hey everyone!

I've begun to produce some acetic acid (vinegar) by culturing some mother of vinegar. I've read that, pure acetic acid can be a potent solvent, however, separating it from water is tricky, since they're both matching azeotropes and not even fractional distillation will work out.

Does anyone know of any cheap(ish) method to accomplish this? (Im not that interested in getting a very pure batch, 50% or more is good enough for me).
27
Organic Chemistry Forum / Re: Carvone and tartaric acid
« Last post by rolnor on Yesterday at 08:59:26 AM »
I think you would get 1,4-addition if you mix the ketone with amine.
28
Organic Chemistry Forum / Caffeine in energy drinks
« Last post by Hauslabuland on Yesterday at 08:52:29 AM »
Hello, everyone. I wonder if caffeine exists alone in energy drinks, such as Red Bull unlike caffeine in tea leaves. I found out that caffeine in tea leaves exists together with tannins. What about caffeine in energy drinks? If someone here knows, I would be happy if you tell me that, please.
29
Organic Chemistry Forum / Re: Carvone and tartaric acid
« Last post by Babcock_Hall on Yesterday at 08:35:49 AM »
Alcohols can react with ketones, but I am not sure what was done in this particular instance.
30
Organic Chemistry Forum / Re: Carvone and tartaric acid
« Last post by AWK on Yesterday at 07:51:54 AM »
For the crystallization of diastereomeric salts, a suitable tartaric acid derivative (most often dibenzoyl tartaric acid) and a suitable solvent or solvent mixture must be found. This is done by trial and error.
But nowadays, racemic mixtures are most often separated by chromatography using chiral stationary phases.
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