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1500 questions
23
votes
3 answers
Where does computational chemistry overlap with organic chemistry?
I was wondering what research exists that combines computational chemistry and organic chemistry.
For the past three years, I've been using Amber and Gaussian (in hopes) to identify and understand trends in intramolecular interactions. This really…
Melanie Shebel
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23
votes
1 answer
Skeletal formula for carbon with two double bonds
How do I depict an sp-hybridised carbon with two double bonds?
$$\ce{R=C=R}$$
If I just leave it out, like I would for a normal $\mathrm{sp^3}$ or $\mathrm{sp}$ carbon, it's difficult to see that it's there.
Matt
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23
votes
2 answers
Derivation of the Heisenberg uncertainty principle
The Heisenberg uncertainty principle states that
$$\Delta x \Delta p \geq \frac{\hbar}{2}$$
where
$\Delta x$ is the uncertainty in the position,
$\Delta p$ is the uncertainty in linear momentum, and
$\hbar = 1.054571800(13) \times 10^{-34}\…
orthocresol
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23
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2 answers
Why does meltwater taste different?
I've noticed that water obtained from melting ice cubes (by keeping them in the open) tastes different from water cooled to the same temperature.
Furthermore, the taste goes away if you keep it in the open for a sufficient duration of time.
I can…
ManishEarth
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23
votes
3 answers
Why do SN2 reactions of alkyl halides proceed differently with KCN and AgCN?
Alkyl halides react with $\ce{KCN}$ to form alkyl cyanides as the main product, whereas the use of $\ce{AgCN}$ leads to isocyanides as the chief product. Why does this happen?
Mohd Shakib
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23
votes
1 answer
Is a compound aromatic if it also has anti-aromatic rings?
Is 5,6,11,12-tetradehydrodibenzo[a,e][8]annulene aromatic?
If I use Hückel's rule for the whole molecule, I get the answer as anti-aromatic. But the compound has two benzene rings which are individually aromatic.
Aditya Dev
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23
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3 answers
What open-source software can produce 3D PDF representation of molecules?
Most of the existing software I know (like VMD or Pymol) say that they can be used to create PDF files with 3D representations of molecules: actual 3D models, which you can rotate inside the Adobe Acrobat viewer. However, they all require the use of…
F'x
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23
votes
2 answers
Why don't everyday things burn?
Ok, so I learned about the equilibrium constant. Now, I've seen that the equilibrium constant of burning is extremely small $(K \ll 1)$. here, I have a question. you see, $K$ is still NOT 0, which means that the forward reactions happen at least a…
Danny Han
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23
votes
2 answers
Silver and milk (or milk products)
In the title I am refering to silver spoons, which, when used to consume milk products (like yogurt), get a weird taste. It could be described as umami/meaty, a little bit like onions. I came to the conclusion that it must be the silver, because…
Evgeni
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23
votes
2 answers
Why do XeO and XeF8 not exist?
Since Neil Bartlett's 1962 discovery that xenon was capable of forming chemical compounds, a large number of xenon compounds have been discovered and described. Almost all known xenon compounds contain the electronegative atoms fluorine or oxygen.…
Nilay Ghosh
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23
votes
2 answers
Vinegar and baking soda: Cleaning agent or neutralized sludge?
I've seen it suggested countless times that combining vinegar and baking soda is a great home cleaning solution, but this always seemed like nonsense to me.
I recognize that baking soda, a base, can eat away at certain kinds of grime and that…
Jason Kleban
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23
votes
2 answers
Why don't trigonal S and P compounds undergo inversion at room temperature?
Most molecules containing nitrogen atoms in trigonal pyramid configuration undergo a relatively fast process of inversion at room temperature. On the other hand, the free energy barrier for phosphines, sulfoniums and sulfoxides are high enough that…
F'x
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23
votes
6 answers
Are there any ionic amorphous solids?
This question on NaCl crystalization actually got me wondering: are there any ionic amorphous solids? Like ionic crystals are crystalline materials of electrostatically-attracted ions, can ions form an amorphous phase? I can see no reason why not,…
F'x
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23
votes
1 answer
Why do we have an alkyl shift rather than epoxidation in a pinacol reaction?
Why do we have an alkyl shift rather than epoxidation in a pinacol reaction?
I don't understand why the hydroxyl group doesn't attack the positive charge.
hanna
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23
votes
5 answers
Can gases be "immiscible"?
Anyone know of any examples of gas mixtures that phase separate, analogously to the way immiscible liquids do?
They would have to be extremely non-ideal. I might guess one might have to be much higher molecular weight than the other and at least…
ericksonla
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