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1500 questions
15
votes
6 answers
What easily accessible material has melting point between 500 °C and 590 °C?
Is there an available at home material with the melting point between 500 °C and 590 °C?
Plastics usually melt below 400 °C.
Tin and lead also below that.
Aluminum is melting above 600 °C.
I made a deep search around the web with no success.
xchcui
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4 answers
Can osmium react with oxygen at room temperature?
I’m an avid collector of elements (I love shiny rocks - don’t judge).
I’m looking to buy some osmium, as it’s one of the heaviest and hardest metals out there.
However, people online told me to avoid buying it, because it could react with oxygen…
Mister SirCode
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15
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3 answers
What really happens atomically in an explosion?
Let's say a room is filled with butane, I then throw a cigarette into the room. What happens to the atoms/molecules of the butane when they are in contact with the heat from the cigarette?
wtoh
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2 answers
Dihedral angle of gaseous and crystalline HOOH
Why does hydrogen peroxide exhibit a dihedral angle of $111.5^\circ$ in the gaseous state? And a dihedral angle of $90.2^\circ$ in the crystalline phase?
I know that in general, there is likely to be more hydrogen bonding in the crystalline phase…
Dissenter
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15
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1 answer
Utility of Bent's Rule - What can Bent's rule explain that other qualitative considerations cannot?
Does Bent's rule have any utility? I got a vehement earful for "NO." Points raised by my professor:
Coulombic considerations can be used to rationalize bond angles, strengths, and lengths without the use of Bent's rule.
Orbitals are not real so…
Dissenter
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1 answer
Can you make napalm out of gasoline and orange juice concentrate?
According to the novel Fight Club by Chuck Palahniuk:
The three ways to make napalm: One, you can mix equal parts of
gasoline and frozen orange juice concentrate. Two, you can mix equal
parts of gasoline and diet cola. Three, you can dissolve…
Tomáš Zato
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15
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3 answers
Why can the lone pair not align with the phenyl moiety in 2,6-xylidine?
I am told that for 2,6-xylidine (2,6-dimethylaniline), the amino group cannot line up in such a way that its p-orbital is parallel with respect to the p-orbitals of the carbons in the ring.
I've looked for papers and no one has actually proved to…
Dissenter
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15
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3 answers
How does chlorine form more than 1 bond?
How are perchlorate or chlorate or chlorite ions and their respective acids or compounds formed. $\ce{Cl}$ can't form more than one bond but still...
$\rightarrow$'Perchlorate ion'
$\rightarrow$'Chlorous acid containing Chlorite ion'
…
NeilRoy
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15
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2 answers
Help understanding how "steric effects" are distinct from "electronic effects"?
@jakebeal's excellent answer to Why do animal cells “mistake” rubidium ions for potassium ions? includes the following passage:
In the case of potassium versus sodium, which are both very important in biochemistry, a recently discovered mechanism…
uhoh
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15
votes
1 answer
Why doesn't ionization energy decrease from O to F or F to Ne?
I know that in general, the first ionization energy increases across a period due to increasing nuclear charge, reasonably constant shielding & decreasing atomic radius.
From N to O, however, the I.E anomalously decreases. The reason usually given…
Vulgar Mechanick
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15
votes
5 answers
Can a proton be ejected from an atom?
Consider a neutral atom that has $n$ protons and $n$ electrons. Is it possible to remove a proton from the atom via some technique such as bombardment with another particle or applying an appropriate amount of energy to the system?
Murtuza Vadharia
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15
votes
1 answer
Analysis of post-HF wavefunctions
Hartree-Fock method introduces electron (spin)orbitals and they are commonly used for qualitative rationalization of many molecular properties. However, MOs have meaning only if we ignore electron correlation. Post-HF non-DFT methods build…
permeakra
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15
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5 answers
Is it possible to achieve a level of "truly zero" concentration?
If we take some aqueous solution and dilute it further and further, will the concentration of the solution ever get to zero? I would say no, simply because total dilution implies that all the molecules of the solute have literally disappeared. But,…
Stephen Muga
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1 answer
How can I properly calculate the isoelectric point (pI) of amino acids?
The following amino acid is called lysine. I was asked to calculate its isoelectric point, with the given $\mathrm pK_\mathrm a$ values.
I've searched a lot, and the most helpful post that I found was How do I calculate the isoelectric point of…
Rahul Verma
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15
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5 answers
On heating in the Earth's atmosphere, can magnesium react with nitrogen to form magnesium nitride?
This question is derived from a question asked in my school test.
What happens when a magnesium ribbon is heated in air?
My first response was the formation of magnesium oxide $(\ce{MgO})$ when oxygen in air reacts with magnesium at a high…
Rajdeep Sindhu
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