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1500 questions
14
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3 answers
Can Hückel's rule be applied to inorganic compounds?
Hückel's rule helps us know which molecular orbital, bonding or antibonding contains more electrons, and it is derived from the same. And on the basis of this, we can find out the stability of the compounds.
But, this rule was specifically…
Iceberry
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14
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3 answers
Tape versus 1922 silver coin
I have a 1922 silver half dollar with scotch tape on it. The tape has been on it 50 years plus. It’s dried out and totally adhered to the coin. I’ve soaked it in lemon essential oil and googone but still a lot of tape left, adhered to coin. …
UglyDog
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14
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Deriving a reduction potential from two other reduction potentials
Given:
\begin{align}
\ce{Co^{3+}(aq) + e- &-> Co^{2+}(aq)} & E° &= \pu{+1.82 V} \\
\ce{Co^{2+}(aq) + 2e- &-> Co(s)} & E° &= \pu{-0.28 V}
\end{align}
what is the standard reduction potential for $\ce{Co^{3+}(aq) +3e- -> Co(s)}$?
If I…
Anonymous Duck
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14
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5 answers
Structure of NO2 compound?
What is the correct structure for the $\ce{NO2}$ compound (not ion)? I always thought it was like:
since the negative charge would be residing the on the highly electronegative oxygen, but was reading this blogpost by the guys at WolframAlpha, who…
1110101001
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14
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Use of Δ (delta) to describe alkenes
In a lot of (mainly older) papers discussing organic synthesis, Δ is used to describe alkenes. As far as I know, this is no longer (if ever) IUPAC recommended nomenclature, so I haven't been able to find any reference to its intended use.
The main…
NotEvans.
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14
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Order of dipole moments
What is the order of dipole moments for $\ce{SO3, SiO2, P2O5,}$ and $\ce{Cl2O7}$? This question is from a book and the answer given is $\ce{Cl2O7 < SO3 < P2O5 < SiO2}$. Can someone explain why? When I drew the Lewis structures and applied VSEPR…
Tyrell Gord
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14
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2 answers
Molecular orbital diagram and irreducible representations for dinitrogen
I'm trying to understand how to draw molecular orbital diagrams, since I'd like to use the molecular orbitals to determine the total state of the molecule (i.e. $A_1$, $B_1$ etc.), so I prefer the notation with irreducible representations of…
Eenoku
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1 answer
Acidity order of 4-halophenols
How do I theoretically predict the acidity order of the following para-halophenols?
(experimental $\mathrm{p}K\mathrm{a}$ values beside each)
parafluorophenol (9.92)
parachlorophenol (9.41)
parabromophenol (9.17)
paraiodophenol (9.30)
Experimental…
Archer
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14
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1 answer
Are there any (simple) molecules with very different absorption and emission dipole directions?
When a single molecule absorbs or emits light, it does so perpendicular to the direction of the respective transition dipole. In principle, the directions of the dipoles for absorption and emission can be different, due to different electronic…
Sentry
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14
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1 answer
Most activated position on para-terphenyl for EAS
Para-terphenyl: it doesn't look pretty with all those math-y numbers, but those are going to come helpful in answering my question!
A question asked me to tell the expected product when this reacts with $\ce{Br2/FeBr3}$. Now, I have done such…
Gaurang Tandon
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14
votes
2 answers
How to identify hydrogen bonds and other non-covalent interactions from structure considerations?
Chemistry is governed by a wide range of interactions, from ionic and covalent bonding, or other types of strong interactions, towards weaker types of bonding, attraction, or repulsion, that typically occur between molecules. The latter are often…
Martin - マーチン
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14
votes
3 answers
Which is the most acidic hydrogen in vitamin C
I thought it would be the lower first $\ce{-OH}$ because it's close to the double bond with oxygen, so I thought there would be more electron withdrawal from the oxygen atom due to its electronegativity.But the correct answer is actually the second…
Isha Roy
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14
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1 answer
Oxidation of naphthalene with KMnO4
What is the product when naphthalene is oxidized by alkaline (or acidic) solutions of $\ce{KMnO4}$?
Some possible reactions show up in a google search, but they have no references:
Naphthalene to phthalic acid by alkaline $\ce{KMnO4}$:
Another…
S R Maiti
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14
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3 answers
Typography of multi-letter variables
Chemical elements are typeset with upright font ($\ce{H2O}$ for water) while variables are typeset with an italic font ($V$ for volume).
But is there a convention what to do with multi-letter variables like IC50, EC50 (or others without subscripts)?…
mhchem
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14
votes
4 answers
Why are MD (Molecular Dynamics) simulations performed at room temperature for the purposes of studying proteins?
All of the MD simulations which are cited in the literature seem to be performed at room temperature (~300 Kelvins), while enzymes are usually bioactive at body temperature (~310 Kelvins).
I am wondering why not just use 310 K for the MD…
Astronomer
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