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18
votes
1 answer
Hyperlithiated Carbon Species
Below is replicated Question 1 from the Final Qualifying Exam of the Australian Chemistry Olympiad, 2004B, here.
Question:
The theory of promotion-hybridization is quite successful at explaining why covalent molecules with a central atom from period…
Chronocanth
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18
votes
4 answers
Why do the melting and boiling points of the noble gases increase when the atomic number increases?
What causes the melting and boiling points of noble gases to rise when the atomic number increases? What role do the valence electrons play in this?
Ali Mustafa
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18
votes
2 answers
How to properly dispose of sodium...or store it properly
While performing an inventory of my school's chemical storage closet today, my fellow teacher and I found some sodium tucked away in the back corner of our flammables cabinet. One container appears to have leaked the oil the sodium was being stored…
Meg Coates
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17
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1 answer
What happens to water under high pressures without possibility of escape?
Knowing very little about the nature of water, wondering how it might behave at the centre of a planet or centre of an another massive gravitational body.
Could water take such pressures or might it break into separate hydrogen and oxygen to find…
irth
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17
votes
3 answers
Why does having equivalent resonance structures give more stability?
Although the phenolate ion has more resonance structures (4) compared to acetate ion (2), acetate is more stable because it has two equivalent resonance structures of same energy.
Why does having equivalent resonance structures give more stability?…
Heisenberg
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17
votes
1 answer
Understanding the synthesis of twistane
What are the products P and Q?
This was a question in my test series, but I don't have any experience with bridge head compound regarding the cis and trans transformation. I need help understanding this process.
Greninja
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17
votes
2 answers
Why does free chlorine in the stratosphere lose its ozone-depleting potential after about 100,000 reactions?
Free chlorine ($\ce{Cl}$) in the stratosphere can deplete ozone ($\ce{O3}$) as follows:
$$\ce{Cl + O3 -> ClO + O2}$$
The chlorine atoms can then react with oxygen and return to the beginning of the cycle:
$$\ce{ClO + O -> Cl + O2}$$
The EPA…
wchargin
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17
votes
1 answer
Directionality of ring current-induced magnetic fields in purines
What would be the directions of ring current-induced magnetic fields in purine-like heterocycles in a strong magnetic field?
Would be the antiparallel state be a default state for these substances in the absence of strong magnetic field at warm…
Max Rempel
- 171
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17
votes
2 answers
What are the alternatives to the Periodic Table of the Elements?
What are the different diagrams/tables used to organize the elements other than the Periodic Table? What are the advantages/disadvantages of each?
RandomDuck.NET
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17
votes
1 answer
Why is the melting point of PCl3 less than that of PCl5?
From just the IB chemistry bonding chapter information, you would normally deduce that $\ce{PCl3}$ and $\ce{PCl5}$ are both covalent molecules.
However, as $\ce{PCl3}$ has a dipole moment, it has dipole-dipole intermolecular attractions, implying…
Stone
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17
votes
1 answer
What is the melting point of diamond?
Textbooks and the online reference differ about this and there are more than two answers.
user3286264
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17
votes
4 answers
Is the strength of hydrogen bonding greater in hydrogen peroxide or water?
When we compare water and hydrogen peroxide's hydrogen bond strength, which one should have the greater one? I know that peroxide has more hydrogen bonds, but when we compare the strength of each hydrogen bond, which one would be greater?
Online…
YAHB
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17
votes
4 answers
Does a diatomic gas have one or two vibrational degrees of freedom?
Many sources claim that the vibrational degrees of freedom for a diatomic gas is one, but there are also a few which claim it to be two. Which is correct, and why is there even any ambiguity to begin with?
Holy Answerer
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17
votes
2 answers
Analytical solution for kinetics of bimolecular reaction
Consider two chemicals, $\ce{A}$ and $\ce{B}$ that react with each other to make $\ce{C}$ with a reaction rate $k$. The reaction can be expressed as $$\ce{A + B->C}$$ The equation expressing the rate of the reactions can be expressed as…
BarocliniCplusplus
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17
votes
1 answer
Why does a Diels–Alder reaction not occur here?
I have recently come across this organic chemistry problem.
I thought it would undergo simple Diels–Alder reaction
But it didn't turn out to be. The product to me looks like a nucleophilic attack of (I) on (II).
Can anybody say me why exactly…
Suraj S
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