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Do Cyclohexane-1,3-diones Give Positive Haloform Reactions?
Recently a post appeared on ChemSE asking why cyclohexane-1,3-dione (dihydroresorcinol) 1a doesn’t give a positive iodoform test. Unfortunately, the post was subsequently taken down after several comments. A paper by Fuson and Bull[1] reviewed the…
user55119
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Why did life end up with the big 4 elements, and specifically nitrogen?
This question is mostly about the human body, but it's also about life in general.
It's not difficult to notice a big different between the abundance of elements on Earth & that in the body. I've been pondering why. Such a huge question, but here I…
longtry
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What is a word for "atom or molecule"?
What is a word for "atom or molecule"? As in: "The entry of an atom or molecule across a cell membrane into a cell is dependent on its size and solubility." This keeps coming up, and it's really irritating (on par with the lack of a good word for…
DrCopeland
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Why is the definition of the mole as it is?
I have asked my teacher, as she was introducing the concept of mole to us, why that number was chosen, instead of more convenient one. She told me that it came from the definition of the mole, that is the number of atoms in 12g of Carbon 12. When I…
Oliver
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What exactly is meant by 'multi-configurational' and 'multireference'?
Some topics here have touched on this before (see 1, 2, 3), but I haven't found a clear definition yet.
I would like to know what exact property of the wave function these terms refer to. It would also be helpful to have a clear definition of…
snurden
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Why do some chemical reactions require many steps?
I posted the following question in Physics SE and was advised to transfer it to Chemistry SE.
I studied physics in college ten years ago and I recently started to learn biochemistry. I enjoy finding out that some familiar concepts in physics play…
Light Yagmi
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Reason for the stronger acidic property of phenol than alcohol
In phenol, pulling the $\mathrm{p}_z$ electrons from the oxygen atom into the ring causes the hydrogen atom to be more partially positive than it is in aliphatic alcohols. This means it is much more easily lost from phenol than it is from aliphatic…
Eliza
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How does water evaporate completely when at room temperature?
If water evaporates at room temperature because a small percentage of the molecules have enough energy to escape into the air, then why does a kitchen counter with a small amount of water eventually evaporate completely when at room temperature?
Carl Wong
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Why do n AOs only form n MOs?
The textbooks I have read introduce LCAO by considering the H2 molecule. In this example, there are only two possible combinations of the two 1s orbitals (in phase and out of phase).
When there are more than two valence orbitals, however, a greater…
Adroit
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How were elements and molecular formulæ determined in the old days?
Before modern chemical techniques, say in the 19th century and earlier, how did (al)chemists determine whether a substance was an element or a compound? If it was a compound, how did they determine its molecular formula and structure?
Nick
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Is pure water very corrosive?
On Outdoors StackExchange on a post about the safety of distilled water, someone claimed that pure water is very corrosive.
Water distilled for some laboratory uses (like the Z-pinch reactor) is distilled to 0.00000009% purity, and is caustic…
jinawee
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How was it concluded that the H3O+ rather than H+ is the "acid" ion?
I suspect that initially, scientists believed that the acid ion was $\ce{H^+}$ since $\ce{H2}$ is released through electrolysis, right? But what experiment was done to change the standpoint to assume that it is instead the $\ce{H3O^+}$ ion?
Or…
skyking
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pH probe bulb - what is happening within the glass?
I am trying to understand how the glass bulb of a pH electrode of a pH meter works - the glass bulb itself. Not the reference electrode or the rest of the electrode (HCl, Ag/AgCl wire, etc...), the math, or the equilibrium yet. For this question…
uhoh
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Why does NaBH4 reduce double bonds conjugated to carbonyl groups, while LiAlH4 does not?
I have been going through reduction of aldehydes using $\ce{LiAlH4}$ and $\ce{NaBH4}$. If there is a double bond conjugated with the carbonyl group, $\ce{LiAlH4}$ doesn't reduce it, leading to an allylic alcohol. However, using $\ce{NaBH4}$, some of…
Rajath Radhakrishnan
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What does the newest IUPAC nomenclature have against unsaturation?
IUPAC nomenclature 2013 changed a couple of rules very commonly used in naming simple acyclic compounds. As a result, depending on which nomencalture we choose, the answer to this question varies greatly, as demonstrated in the comments. Educational…
M.A.R.
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