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1500 questions
16
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Is there a preferred way of naming the resonance hybrid in keto-enol tautomerism?
While answering a question about keto-enol tautomerism the question arose, how can I refer to the resonance hybrid instead of on of the resonance forms. In the case of the deprotonated butane-2-one, I can name 1 3-oxobutan-2-ide and 2 but-2-en-olate…
Martin - マーチン
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16
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Do there exist metals that are composed of molecules?
Most metals are composed of pure elements or are alloys (mixtures of pure elements.)
Are there metals that are composed of one type of molecule that is metallically bonded together?
The difference between a metal that is composed of one type of…
Molly Stewart-Gallus
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16
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Why are 7-membered rings less likely to form than 5- and 6- membered rings?
I see 5- and 6-membered ring products as the major products even when 7-membered rings are possible. Why is that 5- and 6-membered rings are more likely to form than 7-membered rings? Is it even true?
My textbook says a 5-membered ring is the major…
Yashas
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16
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What is Cβ (C-beta) deviation?
Molprobity and some other protein structure validation tools report a Cβ deviation statistic and offer plots for it (example below). Apparently if the Cβ is greater than 0.25 Å, some attention should be given to the residue.
The statistic is given…
Nick T
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16
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What was the lithium concentration in 1940's 7-Up?
I just came across this article in the New York Times, where lithium (or more correctly, lithium salts), a known anti-depressant had been added to beverages in the 1940's. They also mention that a study found negative correlation between the suicide…
snurden
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16
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2 answers
Chlorination by SOCl2 vs SO2Cl2
My textbook mentions that chlorination of alkanes by $\ce{SO2Cl2}$ is preferred over $\ce{SOCl2}$, but I didn't understand why.
Could someone explain which of the two reagents I should use in what situations, and briefly tell me why?
There is a…
Mahathi Vempati
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16
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Nucleophilicity/basicity in protic and aprotic solvents
In polar aprotic solvent, why is $\ce{F-}$ a stronger nucleophile than $\ce{I-}$?
What I think: If I talk about their basicity, $\ce{F-}$ would be more basic due to instability from its high electron density. Is it applied same when talking about…
NK Yu
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16
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2 answers
What are the mechanisms for capture of As(III) and As(V) by magnetite from water?
Magnetite, $\ce{Fe3O4}$ is able to capture $\ce{As(III)}$ and $\ce{As(V)}$ from drinking water through the following mechanisms.
Bidentate-binuclear complex
Monodentate-binuclear complex (both from here)
I'm assuming these are standard…
jonsca
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16
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2 answers
Is circularly polarized light ever used to isolate particular chiralities?
Chiral molecules tend to absorb one circular polarization of light more than the other. Is this ever used to isolate a particular enantiomer?
Dan
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Cr(II) and Mn(III) - their oxidizing and reducing properties?
My textbook states that $\ce{Cr^2+}$ is a reducing agent while $\ce{Mn^3+}$ is an oxidizing agent in spite of both having $\ce{d^4}$ configuration. The explanation states that when $\ce{Cr^2+}$ gets oxidized to $\ce{Cr^3+}$, it attains a stable…
vamsi3
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16
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1 answer
Explaining the Relative Energies of Various Vibrational Modes
Specifically, I'm wondering why it is that the asymmetric stretch in most (although there are exceptions to this I believe) molecules is higher in energy than the symmetric stretch.
Similarly, I would like a nice, physical (ideally…
jheindel
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16
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How are non-carbon stereogenic centers named (S/R)?
The R/S naming system for stereocenters relies on the Cahn–Ingold–Prelog priority rules to rank the four substituents of a stereocenter; the R or S name is then attributed depending on the spatial orientation of the ranked substituents. While this…
F'x
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16
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Why are tertiary carbocations so stable?
Today our lecturer provided this data to illustrate the relative stability of carbocations.
\begin{array}{|c|c|c|c|c|} \hline
\text{Substrate} & \ce{t-BuBr} & \ce{i-PrBr} & \ce{EtBr} & \text{MeBr}\\ \hline
\mathrm{Relative~rate~of~S_N1~reaction} &…
bon
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5 answers
Is there a way to use free software to convert SMILES strings to structures?
So far I've been unsuccessful in finding an open source tool that will convert a large number (>100k) of SMILES strings to a chemical structure.
Is this really only solved by commercial applications?
I would not mind converting through a number of…
BootstrapBill
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What is the product of the chemical reaction between phenol and ferric chloride?
The chemical reaction between phenol and ferric chloride is a test for the presence of phenol. They react with each other to produce a violet complex. However, the reaction is given differently in different links:
$$\ce{3ArOH + FeCl3 → Fe(OAr)3 +…
Nilay Ghosh
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