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Use this tag for questions relating to organic molecules and their properties (structure of organic molecules, spectroscopic properties, reaction mechanisms, stereochemistry etc). DO NOT use this tag as the only tag in your question, as this tag by itself cannot appropriately classify your question. Always use this tag in addition to other more specific tags.
3
votes
Formaldehyde (37%) storage
In the cold some paraformaldehyde (formaldehyde polymer) or trioxymethane (a cyclic condensation product of three formaldehydes) may precipitate.
It will depend on how much methanol has been added to …
5
votes
Accepted
What quantity of dessicant agent
You add dissicant until it suspends easily in the solvent when you swirl the flask. Some people say: "Until it snows".
When you add a bit of magnesium sulfate or other fine powdered dissicant, it for …
0
votes
what is the product of this reaction and mechanism?
Yes, the oxigen is protonated, water enters, methanol leaves and another $\ce{H^+}$ is released.
Then the oxigen of the other $\ce{CH3O}$ group is protonated, the keto group is formed while the methan …
4
votes
Accepted
What happened when the cherry juice turned blue?
Cherries, like red cabbage, hibiscus and many red or purple colored fruits, contain a class of compounds called anthocyanins of general formula:
where $\ce{R_x}$ is either $\ce{OH}$, $\ce{OR}$ or $ …
0
votes
Accepted
Percentage of trans-stilbene traces in cis-stilbene H NMR
You have to focus on the $\ce{^1H}$ of the double bond.
They are singlets because both molecules are completely symmetrical.
As per the tables, the chemical shift of the cis isomer is $5.25+1.38-0.0 …
6
votes
Accepted
Reason behind conversion of acid to acid bromide in Hell-Volhard-Zelinsky reaction
The $\alpha$ halogenation occurs through the enol form.
The formation of the acyl halide is key because carboxylic acids do not form enols readily since carboxylic acid proton is removed before the …
1
vote
Biological contamination from ground
The point is not how large the possibility is.
There is a possibility that the flask has been contaminated, so you should have taken a new flask.
I suppose you did not have a spare one with you.
Th …
4
votes
What is the structure of 92 m/z fragment for aspirin
This spectrum is recorded using electron impact. That means that the molecule is positively charged by losing one electron.
Since that is a very unstable structure, the molecule starts fragmenting lo …
0
votes
Accepted
What is the difference, if there is, between this two distillation methods?
There is no fundamental difference between the two methods.
In both cases steam is formed and it is passed through the plant material.
The intention is to extract the non volatile water insoluble es …
4
votes
Accepted
Reaction of 2,4-DNPH with aromatic aldehydes
2,4-DNPH is a derivatization reagent for the identification of ketones and aldehydes.
This was extensively used in organic analysis before instrumental methods were readily available.
You determined …
1
vote
How good is aromaticity at stabilization?
The situation in S and P is very similar.
Essentially you have a negative charge $\alpha$ to two double bonds which will delocalize these charges.
In the case of cyclopentadiene, this will be stabili …
3
votes
Accepted
Why do orthoesters react with Grignard reagents, but acetals and ketals don't?
Grignard reactions are performed in ether or THF.
There you have only one -OR group on a carbon and, since it is the solvent, it is not reacting with it.
This shows that not always a -OR group is subs …
5
votes
Major product in Reimer-Tiemann Carbonylation
You are right in that the $\ce{OH}$ is the main director, especially in alkaline media.
The para position is preferred over ortho because it has less sterical hindrance.
Therefore, the major produc …
2
votes
Soxhlet extraction condenser - addition of compound to refluxing setup
In my opinion the intention is to have a very slow addition of the reagent to the hydride. The compound is dissolved in ether, so a Soxhlet is of no use since it is for solids.
What they are possibl …
2
votes
Methods for dissolving Scotch/Kaptop/etc. Tape for Electron Microscopy?
Kapton is a polyimide:
It contains an $\ce{N}$ substituted phtalimide as a substructure.
This kind of compound is used in the Gabriel synthesis to make primary amines.
The synthesis is very ingen …