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1500 questions
18
votes
3 answers
Orthogonal Wavefunctions
My current understanding of orthogonal wavefunctions is: two wavefunctions that are perpendicular to each other and must satisfy the following equation: $$\int\psi_1\, \psi_2\, \mathrm{d}\tau =0$$
From this, it implies that orthogonality is a…
user22450
18
votes
2 answers
Protons and the Heisenberg principle
The Heisenberg uncertainty principle implies that it is not possible to calculate the position and velocity of a body at the same time accurately. Electrons follow this principle since their orbitals are just probabilities where they may occur. But…
anonymous789
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1 answer
What is a sigma complex?
According to Wikipedia, "sigma complex" refers to an arenium ion.
The suffix "-ium" denotes a positively charged ion.
So, it is correct to call the resonance structures in the below picture depictions of a sigma complex? It's distinctly anionic…
Dissenter
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18
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3 answers
Why does mercury form polycations?
For example, mercury (I) is $\ce{Hg2^2+}$ and not $\ce{Hg+}$. What causes the stability in covalently bonded $\ce{Hg}$ ions?
carbenoid
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18
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1 answer
Why does water spills on our shirt change its colour?
While drinking water, some of it spilled on my shirt and as usual, as has happened to many of us, the colour darkened. So why does this happen? Is it due to some chemical effect or physical one?
Chloritone_360
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18
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1 answer
Orbital correlation diagram for the cleavage of cyclopropylmethylene carbene
In the last exam we were asked to rationalize the mechanism of the cyclopropylmethylene carbene cleavage into acetylene and ethylene.
In the lecture we discussed pericyclic reactions (cycloadditions, electrocyclic reactions, sigmatropic reactions,…
laminin
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18
votes
6 answers
Does the Maxwell-Boltzmann distribution apply to gases only?
The Maxwell-Boltzmann distribution can be used to determine the fraction of particles with sufficient energy to react. I know that the curve applies to gaseous reactants and would like to know whether solids and/or liquids are also described by a…
Jaywalker
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18
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1 answer
Analytical solution of the Schrödinger Equation for AB^+ systems
According to Wikipedia, there are not many problems for which the Schrödinger equation can be solved analytically. [1] The $\ce{H2+}$ ion is probably the most complex molecule that can be treated this way.
As far as I know, every diatomic…
pH13 - Yet another Philipp
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18
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3 answers
Pubchem, InChI, SMILES, and uniqueness
PubChem compound 6140 is L-phenylalanine in its neutral (not zwitterionic) form. According this PubChem, this molecule has the following SMILES and InChI indentifiers:
SMILES: C1=CC=C(C=C1)CC(C(=O)O)N
InChI:…
Curt F.
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18
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3 answers
Why is tetraamminecopper(II) a square planar and not a tetrahedral species?
In $\ce{[Cu(NH3)4]^2+}$, the $\ce{Cu^2+}$ ion has 9 electrons in the $\mathrm{3d}$ orbital with only one unpaired electron. How is it a square planar geometry? Where is that unpaired electron going?
Dhruba Banerjee
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18
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3 answers
How to dispose of pure potassium
I have about 2g of 99.5% Potassium.
I want to get rid of it, right now it's in a glass jar sealed.
What is the proper protocol? I was going to combust it in water and wash it down the drain but the by-product potassium hydroxide is caustic and…
Albert Renshaw
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18
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2 answers
Not your ordinary hard water deposit
We have a well that delivers hard water and we do not have a water softener. (There was a “green sand filter” that utilizes permanganate to oxidize other metals on the system, but it has been disconnected.) Analysis of the well water shows the…
Janice DelMar
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18
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2 answers
Why are there peaks in electronegativities in d-block elements?
Looking at the Pauling electronegativities in the Periodic Table (below, from ChemWiki):
Asides from the overall trend of increasing electronegativity across and up the Periodic Table (towards fluorine), there seems to be a minor peak in the first…
user15489
18
votes
2 answers
Is this sydnone aromatic?
Is the following molecule aromatic?
It does seem like it will be aromatic because it is similar to furan. I am confused because of the positive charge on the $\ce{N}$.
Papul
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18
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How many times can we recycle one sheet of paper?
Its really interesting to see the process of recycling of paper (as shown in picture below) but at the same time I was thinking like for how many times can one sheet of paper can be recycled ?
Shashank
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