instruction stringlengths 15 21.8k |
|---|
I recall a paper where heating the hydrate in a stream of $\ce{HCl}$ gas avoided the formation of a basic salt.
This may work for hexahydrate $\ce{AlCl6⋅6H2O}$ also.
**References**
1. https://books.google.com/books?id=Pef47TK5NfkC&pg=PA1147&lpg=PA1147&dq=dehydration+with+a+stream+of+HCl&source=bl&ots=W8NJaeEg... |
I've seen a new paper that says that IH3 and IH5 should be observable. Have anyone actually tried to synthesize such molecules? |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
I've seen a paper by Sikalov \[[1](https://doi.org/10.1007/s00214-019-2524-0)\] that says that $\ce{IH3}$ and $\ce{IH5}$ should be observable. Have anyone actually tried to synthesize such molecules?
### References
1. Sikalov, A. A. Hypervalent Halogen Hydrides $\ce{HalH_n}$ ($\ce{Hal}$ = $\ce{Cl},$ $\ce{Br},$ ... |
Have IH₃ and IH₅ already been synthesized? |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
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 "he or she" in clinical writing talking about patients). English major... |
What is a word for "atom or molecule"? |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
I have read from sources [here][1], [here][2] and even in my textbook that Copper (specifically $\ce{CuCl2}$ ) burns with a bluish green flame. All the sources mention that this is due to electron excitation and de-excitation in the orbitals of Cu. However, **Why is copper the only transition element to give a coloured... |
Just read Wikipedia article on Verdigris again, and it is clear per the preparation path described by Nuygen above, that the product is classic (except for the use of a copper wire in place of a copper plate, with a varying height separation from the 5% vinegar), and accurately detailed by Wikipedia at https://en.wikip... |
I am playing around with a toy model of a transition metal complex where the HOMO are $d$-electron states of predominantly transition metal character. Let's say this is a $d^1$ (or $d^9$) system and the states are split in energy by ligand field effects. The relevant HOMO orbital is some linear combination of $d$-orbit... |
Effective Bohr Radius in Transition Metal Complexes? |
I am playing around with a toy model of a transition metal complex where the HOMO are $d$-electron states of predominantly transition metal character. Let's say this is a $d^1$ (or $d^9$) system and the states are split in energy by ligand field effects. The relevant HOMO orbital is some linear combination of $d$-orbit... |
I am playing around with a toy model of a transition metal complex where the HOMO are $d$-electron states of predominantly transition metal character. Let's say this is a $d^1$ (or $d^9$) system and the states are split in energy by ligand field effects. The relevant HOMO orbital is some linear combination of $d$-orbit... |
I have three histidine residues that are next to each other in a protein. When I compute the fraction of unprotonated states for each individual histidine as a function of $\mathrm{pH}$ my titration curve has a non-Henderson–Hasselbalch (HH) shape. Hence I can't fit it using the HH equation for 1 site:
$$\frac{1}{1 ... |
I had some stearic acid in solid pellet format. It is slippy and in white color. I used this to make some experiments. I recently notice that some manufacturer can supply liquid stearic acid. I checked the books. Stearic acid should be in solid form at room temperature. I was confused.
Would someone help me to underst... |
In October 2019 a series of new transition metal complexes has been reported in an article published in *Nature* by Garçon et al. \[[1](https://doi.org/10.1038/s41586-019-1616-2)\].
A palladium complex **tris([2,6-di(propan-2-yl)phenyl][4-{[2,6-di(propan-2-yl)phenyl]imino}pent-2-en-2-yl]amido)-trihydrido-palladium-t... |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
There is a famous saying that paper never refused an ink, which means anyone can write anything on the paper and the paper won't say anything back to the writer. Internet has made this situation worse. One should develop a healthy level of skepticism when reading website and forums.
> Why is copper the only transit... |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
I have used a machine learning algorithm on QM9 dataset to extract some features. To visualize this feature space, I used a PCA algorithm to project it to a 2D space (in simple words, every point in the figure below represents a molecule). Then, I colored the points by property values of these molecules. For instance, ... |
In a section reviewing **Lewis structure**, the textbook *Atkins' Physical Chemistry, 10th Edition*, by Atkins, Paula, and Keeler, gives the following illustration of **hypervalence** and **octet expansion**:
[![enter image description here][1]][1]
I have two questions regarding this illustration:
1. With rega... |
Please, would you suggest me what i should use to oxidize vitamin c to dehydroascorbic acid instead bromine water? Thank you so much. |
[![lean = a lot of oxygen rich = too much fuel][1]][1]
[![enter image description here][2]][2]
No x conversion is low at oxygen rich conditions because no CO or HC are available for the Reduction.
But why is No x conversion also low at oxygen rich conditions, so an optima exists?
[1]: https://i.stack.imgu... |
Why is NO x conversion low at fuel rich conditions? #tree-way catalytic converter |
[![rich conditions = under stochiometric oxygen][1]][1]
[![enter image description here][2]][2]
No x conversion is low at oxygen rich conditions (lean operation) because no CO or HC are available for the Reduction.
But why is No x conversion also low at oxygen rich conditions, so an optima exists? Rich conditi... |
I have used a machine learning algorithm on QM9 dataset to extract some features. To visualize this feature space, I used a PCA algorithm to project it to a 2D space (in simple words, every point in the figure below represents a molecule). Then, I colored the points by property values of these molecules. For instance, ... |
[![rich conditions = under stochiometric oxygen][1]][1]
[![enter image description here][2]][2]
No x conversion is low at oxygen rich conditions (lean operation) because no CO or HC are available for the Reduction.
But why is No x conversion also low at fuel rich conditions, so an optima exists? Rich condition... |
Does E-factor include all of the reagents including catalysts, solvents, and reactants that go into making the product? Further in the E-factor calculation should all the solvents used in work-up also be included? Such as water and ammonia solution. E factor = total waste (Kg)/product (Kg) = (total reagents - product)(... |
E-factor what does it include? |
[![rich conditions = under stochiometric oxygen][1]][1]
[![enter image description here][2]][2]
$\ce{NO_x}$ conversion is low at oxygen rich conditions (lean operation) because no CO or HC are available for the reduction.
But why is $\ce{NO_x}$ conversion also low at fuel rich conditions, so an optima exists? ... |
Why is NOx conversion low at fuel rich conditions? #three-way catalytic converter |
What would you suggest me to use for oxidation of vitamin C to dehydroascorbic acid instead of bromine water? |
I have three histidine residues that are next to each other in a protein. When I compute the fraction of unprotonated states for each individual histidine as a function of $\mathrm{pH}$ my titration curve has a non-Henderson–Hasselbalch (HH) shape. Hence I can't fit it using the HH equation for 1 site:
$$\frac{1}{1 ... |
In general when we talk about chemical bonding, we say that it is "nature's way to stabilize the systems" and the energy of the molecule formed by atoms will be lower than that of the individual atoms; hence leading to stabilization.
However, while reading about the Molecular Orbital Theory in my NCERT Chemistry Te... |
What is actual difference between neutral oxides (e.g. $\ce{NO},$ $\ce{N2O},$ $\ce{CO})$ and amphoteric oxides (e.g. $\ce{Al2O3})?$ I got a hint of it from [the comment of Ivan Neretin](https://chemistry.stackexchange.com/q/109508/68148). |
In general when we talk about chemical bonding, we say that it is "nature's way to stabilize the systems" and the energy of the molecule formed by atoms will be lower than that of the individual atoms; hence leading to stabilization.
However, while reading about the Molecular Orbital Theory in my NCERT Chemistry Te... |
Knowing the moles of substance per amount of solution would be useful. Pour some solution and you'd know how much substance you have. Why is molality defined not this way, but as moles of substance per solute instead? It seems like this unit was engineered to have a value similar to molarity rather than to be maximally... |
Why is molality per amount of solvent rather than per amount of solution? |
> [![rich conditions = under stochiometric oxygen][1]][1]
> $$
\begin{align}
&\text{Oxidation:} &\quad \ce{2 CO + O2 &-> 2 CO2}\\
& & \ce{``HC" + O2 &-> CO2 + H2O}\\
& & & \\
&\text{Reduction:} &\quad \ce{2 CO + 2 NO &-> 2 CO2 + N2}\\
& & \ce{``HC" + NO &-> CO2 + H2O + N2}
\end{align}
$$
$\ce{NO_x}$ conve... |
Why is NOₓ conversion low at fuel rich conditions in a three-way catalytic converter? |
Does [E-factor](https://en.wikipedia.org/wiki/Green_chemistry_metrics#Environmental_(E)_factor) include all of the reagents including catalysts, solvents, and reactants that go into making the product? Further, in the E-factor calculation should all the solvents used in work-up (such as water and ammonia solution) also... |
What does environmental factor include? |
Knowing the moles of substance per mass of solution would be useful. Pour some solution and you'd know how much substance you have. Why is molality defined not this way, but as moles of substance per mass solute instead? It seems like this unit was engineered to have a value similar to molarity rather than to be maxima... |
Why is molality per mass solvent rather than per mass of solution? |
Knowing the moles of substance per mass of solution would be useful. Pour some solution and you'd know how much substance you have. Why is molality defined not this way, but as moles of substance per mass solute instead? It seems like this unit was engineered to have a value similar to molarity rather than to be maxima... |
Does (H4CO4) exist as a relatively stable compound (like H4SiO4)? |
How does H3O+ form Aldehyde from epoxide? I thought it would become diol..Am I wrong?
[![Question][1]][1]
[![My thoughts][2]][2]
[1]: https://i.stack.imgur.com/Z4uL8.png
[2]: https://i.stack.imgur.com/sp2aw.png |
Epoxide and H3O+ reaction? |
$\ce{CH3CH2CH2Br + OH- \bond{->} CH3CH2CH2OH + Br-}$
$\ce{Rate of reaction = k[CH3CH2CH2Br][OH-]}$
If I change the Br with any element from halides (without changing concentration, volume, mass etc.), does the rate of reaction change? If so, how does it change? What factors change it? |
Are the reaction rates of these equations equal? |
Does clove oil/eugenol interact with nylon type plastics? |
$\ce{CH3CH2CH2Br + OH- \bond{->} CH3CH2CH2OH + Br-}$
$\ce{Rate of reaction = k[CH3CH2CH2Br][OH-]}$
If I change the Br with any element from halogens (without changing concentration, volume, mass etc.), does the rate of reaction change? If so, how does it change? What factors change it? |
Does $\ce{H4CO4}$ exist as a relatively stable compound like $\ce{H4SiO4}?$ |
Does H₄CO₄ exist? |
$$\ce{CH3CH2CH2Br + OH- -> CH3CH2CH2OH + Br-}$$
$$\mathrm{rate} = k[\ce{CH3CH2CH2Br}][\ce{OH-}]$$
If I change the $\ce{Br}$ with any element from halogens (without changing concentration, volume, mass etc.), does the rate of reaction change? If so, how does it change? What factors change it? |
> $$\ce{CH3CH=CH2 ->[?] CH3-CHBr-CH2Br}$$
In the reaction mechanism, why does the nucleophile attack at the 2nd carbon atom ? Shouldn't it attack at the 1st one, so that in the transition state, the carbanion is relatively more stable ? |
What will be the major product of the reaction?
I guess that rearrangement will take place and give 5-bromo-5-methylhex-2-ene as a product, but I'm completely not sure |
Why doesn't $\ce{H4CO4}$ exist as a relatively stable compound ? |
Why does H₄CO₄ exist as a stable compound? |
> $$\ce{CH3CH=CH2 ->[Br2] CH3-CHBr-CH2Br}$$
In the reaction mechanism, why does the nucleophile attack at the 2nd carbon atom? Shouldn't it attack at the 1st one, so that in the transition state, the carbanion is relatively more stable? |
For the reaction kinetic rate constants, there is the well known [Arrhenius equation][1]:
$$k=A \cdot \exp{(-\frac{E_\mathrm{a}}{RT})}$$
$A$ is sometimes called frequency factor, interpreted as the rate of collisions with the proper orientation of molecules.
It has 2 terms:
1. The rate of general collisions, that ... |
While reading about p-block I got to know that in Group 15 elements
"electronegativity value decrease down the group but amongst the heavier elements difference is not that much pronounced."
I understood that electronegativity decrease down the group as the atomic size increase but I don't understand that why in he... |
For the reaction kinetic rate constants, there is the well known [Arrhenius equation][1]:
$$k=A \cdot \exp{\left(-\frac{E_\mathrm{a}}{RT}\right)}$$
$A$ is sometimes called frequency factor, interpreted as the rate of collisions with the proper orientation of molecules.
It has 2 terms:
1. The rate of genera... |
For the reaction kinetic rate constants, there is the well known [Arrhenius equation][1]:
$$k=A \cdot \exp{\left(-\frac{E_\mathrm{a}}{RT}\right)}$$
$A$ is sometimes called frequency factor, interpreted as the rate of collisions with the proper orientation of molecules.
It has 2 terms:
1. The rate of genera... |
In structure of Dihydrogen peroxy-phosphate ion $\ce{H2PO5-}$, shouldn't negative charge be on oxygen linked directly to phosphorus, rather than on oxygen linked through peroxy linkage with another oxygen? Since in former it will be in resonance with $\mathrm{p}\pi-\mathrm{d}\pi$ multiple bond between phosphorus and ox... |
What is be the best commercially available source of highly nucleophilic **iodide** in non-polar solvent? Solvents used are cyclohexane, benzene, chlorobenzene.
I can get ahold of bromide quaternary ammonium salts at best. So I'm looking for equal substituent of Bu4NI. Any ideas? |
What is the difference between stoichiometric coefficients and number of moles? |
For the reaction kinetic rate constants, there is the well known [Arrhenius equation][1]:
$$k=A \cdot \exp{\left(-\frac{E_\mathrm{a}}{RT}\right)}$$
$A$ is sometimes called frequency factor, interpreted as the rate of collisions with the proper orientation of molecules.
It has 2 terms:
1. The rate of genera... |
For the reaction kinetic rate constants, there is the well known [Arrhenius equation][1]:
$$k=A \cdot \exp{\left(-\frac{E_\mathrm{a}}{RT}\right)}$$
$A$ is sometimes called frequency factor, interpreted as the rate of collisions with the proper orientation of molecules.
It has 2 terms:
1. The rate of genera... |
In *Organic Chemistry Lab Techniques* (Nichols), I found this diagram.
[![enter image description here][1]][1]
I understand that when going from Point A to Point B, the composition becomes richer in the more volatile component (component A).
However, why does condensation of the vapor at Point B not change th... |
Why is the composition of a liquified vapor the same as that of the vapor? |
How does $\ce{H3O+}$ form Aldehyde from epoxide? I thought it would become diol. Am I wrong?
[![Question][1]][1]
[![My thoughts][2]][2]
[1]: https://i.stack.imgur.com/Z4uL8.png
[2]: https://i.stack.imgur.com/sp2aw.png |
In *Organic Chemistry Lab Techniques* (Nichols), I found this diagram.
[![enter image description here][1]][1]
I understand that when going from Point $a$ to Point $b$, the composition becomes richer in the more volatile component (component A).
However, why does condensation of the vapor at Point $b$ not cha... |
While reading about p-block I got to know that in Group 15 elements
>electronegativity value decrease down the group but amongst the heavier elements difference is not that much pronounced.
I understood that electronegativity decrease down the group as the atomic size increase but I don't understand why in heavier... |
Wikipedia, in the article on Orbital Hybridisation, states the following:
> One misconception concerning orbital hybridisation is that it incorrectly predicts the ultraviolet photoelectron spectra of many molecules. While this is true if Koopmans' theorem is applied to localised hybrids, **quantum mechanics requires... |
What about NiCl2(dppe) makes it a more efficient catalyst for Suzuki cross-coupling as opposed to NiCl2(PPh3)2 or NiCl2(PCy3)2? How does the dppe ligand increase the reactivity of the catalyst? |
Triphenylphosphine vs. dppe ligand? |
How does $\ce{H3O+}$ cause the formation of an aldehyde from the following epoxide? I thought that the epoxide would undergo opening to form a 1,2-diol. Am I wrong?
[![Question][1]][1]
[![My thoughts][2]][2]
[1]: https://i.stack.imgur.com/Z4uL8.png
[2]: https://i.stack.imgur.com/sp2aw.png |
could a fire with it's fuel consisting of mostly carbon like coal or wood use chlorine instead of oxygen. My thinking goes that when fire burns it sucks in oxygen and that bonds with carbon to make carbon dioxide. So... if you had chlorine instead of oxygen would the chlorine bond with the carbon and make Carbon tetrac... |
How does $\ce{H3O+}$ cause the formation of an aldehyde from the following epoxide?
[![Actual product][1]][1]
I thought that the epoxide would undergo opening to form a 1,2-diol, as illustrated below. Am I wrong?
[![My thoughts][2]][2]
[1]: https://i.stack.imgur.com/L9VyA.png
[2]: https://i.stack.img... |
I recently read an [article on Wikipedia](https://en.wikipedia.org/wiki/Pentagonal_planar_molecular_geometry) about pentagonal planar geometry.
There are only two molecules with this kind of geometry $\ce{XeF5-}$ and $\ce{IF5^2-}$ and it has two electron pairs at the axial positions.
As soon as I looked [at th... |
Do molecules with a hexagonal planar geometry exist? |
I have used a machine learning algorithm on QM9 dataset to extract some features. To visualize this feature space, I used a PCA algorithm to project it to a 2D space (in simple words, every point in the figure below represents a molecule). Then, I colored the points by property values of these molecules. For instance, ... |
What about $\ce{NiCl2(dppe)}$ makes it a more efficient catalyst for Suzuki cross-coupling as opposed to $\ce{NiCl2(PPh3)2}$ or $\ce{NiCl2(PCy3)2}$? How does the dppe ligand increase the reactivity of the catalyst? |
Triphenylphosphine (PPh3) vs. 1,2-bis(diphenylphosphino)ethane (dppe) ligand? |
I came across a term "millamolecule" to represent *macrocycles with a molecular weight between 500 and 1,000 daltons*. Google Scholar several resources which use this term e.g., [Google Scholar Results][1]
What could be origin of this term or is it just a buzzword invented by pharma companies?
[1]: https://sc... |
I came across a term "millamolecule" to represent *macrocycles with a molecular weight between 500 and 1,000 daltons*. Google Scholar show several resources which use this term e.g., [Google Scholar Results][1]
What could be origin of this term or is it just a buzzword invented by pharma companies?
[1]: https... |
I used also Iron, Nickel, Zinc, Copper. However, Cobalts gives the easiest and straight forward yield of nitrides. (XPS and SAED verified).
It is so easy to get cobalt nitride that I don't even have to use high purity nitrogen as I need with $\ce{Fe, Ni, Zn, Cu}$.
Is there any reason for that? Is it because of bac... |
[Molality][1] $b$ is defined its way because being proportional for the given solvent to the solute/solvent molecular ratio.
Molarity or molar/mass fractions or molar_amount/solution_mass are not proportional to it.
The boiling and melting point shifts are proportional via ebullioscopic/kryoscopic solvent constants ... |
I was looking through the literature when I found a paper by Greenzaid et al. \[[1](https://doi.org/10.1039/TF9676302131)\] which states that the equilibrium constant $K_\mathrm{hyd}$ is:
> $$K_\mathrm{hyd} = [\text{hydrate}]/[\text{carbonyl}] = (\varepsilon_0^\mathrm{w} - \varepsilon^\mathrm{w})/\varepsilon^\mathrm... |
[Molality][1] $b$ is defined its way because being proportional for the given solvent to the solute/solvent molecular ratio.
Molarity or molar/mass fractions or molar_amount/solution_mass are not proportional to it.
The boiling and melting point shifts are proportional via ebullioscopic/kryoscopic solvent constants ... |
I am trying to find out correlation for Ignition delay for alkane fuels. Activation energy part of correlation gives me negative value.
for ignition delay formulation, Is it possible to have overall activation energy part negative?
[Formulation of Activation Energy][1]
[1]: https://i.stack.imgur.com/VcdrY.g... |
Is it possible to have "negative overall activation energy" for whole chemical mechanism? |
Is there a tool that would help in creating rather intricate *line drawings* (**not** pre-rendered balls-and-sticks/wireframe/sticks/ORTEP diagrams) for a skeletal formula in 3D space?
To illustrate the question a bit further, here are two examples:
1. Organic molecules — An all-benzene catenane and a trefoil kno... |
Is there a tool that would help in creating rather intricate *line drawings* (**not** pre-rendered balls-and-sticks/wireframe/sticks/ORTEP diagrams) for a skeletal formula in 3D space?
To illustrate the question a bit further, here are two examples:
1. Organic molecules — An all-benzene catenane and a trefoil kno... |
How do I convert an Excel file with smiles and IC50 to a.smi file? |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.