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On the face of it it doesn't seem especially difficult.
Model the amino acids as solid objects linked together. Approximate the 3D force fields around them using a coarse approximation, then set the simulation going in a computer and see what happens.
Why is this such a difficult problem that it has taken decades t... |
The difference between bands in liquids and solids is like the difference between [homogeneous and inhomogeneous broadening][1]. In both cases you get bands (a distribution of energies), but in one case it is because of resonant matching of orbitals between different atoms/molecules whereas in the latter it is because ... |
When deriving the integrated rate equations, we start off with r =k[A] for example, and then we do the whole integration thing to find an equation of [A] in terms of time. But why are we ingnoring any other reactants here? Wouldnt the r=k[A][B] if B was was another reactant? |
Why are we finding the integrated rate law by starting with r=k[A]? |
The difference between bands in liquids and solids is reminiscent of the difference between [homogeneous and inhomogeneous broadening][1]. In both cases you get bands (a distribution of energies), but in one case broadening involves delocalization over resonantly matched orbitals on different atoms/molecules and in the... |
The difference between bands in liquids and solids is similar to the difference between [homogeneous and inhomogeneous broadening][1]. In both cases you get bands (a distribution of energies), but in one case broadening involves delocalization over resonantly matched orbitals on different atoms/molecules and in the lat... |
The difference between the origin of bands in liquids and solids is similar to the different cause of [homogeneous and inhomogeneous broadening][1]. In both cases you get bands (a distribution of energies), but in one case broadening involves delocalization over resonantly matched orbitals on different atoms/molecules ... |
>lithium chloride is considered to be an ionic compound,but it is soluble in alcohol,which suggests that it also posses a small amount of covalent character.
This is an extract from my book ,when I looked it up it said ionic bonds are polar so they are soluble in alcohol.
So how does lithium chloride's solubility... |
From time to time, a long spur of ice grows on one “cube” of my ice cube tray.
It’s quite slender, about 3mm or 1/8 inch at the base tapering to about 1mm at the tip, but it’s about 30mm or over 1 inch long!
[![Ice spur][1]][1]
The angle of the spur seems to always be the same - about 45 degrees.
What going... |
Take this is an example:
**HCl** *(aq)* ----------------> **$H^+$***(aq)* + **$Cl^-$***(aq)*
*i.e*
**HCl** *(aq)* + **$H_2 O$** -----------------> $H_3 O^+$ + **$Cl^-$***(aq)*
Clearly the proton latches on to the water molecule but why? Also, why does the hydronium ion has an +ve charge? Did the proton sett... |
Why does a proton react with water to form hydronium ion and why does that ion has an overall +ve charge? |
I've researching electrolysis recently, and all of the examples I've seen use two different metals as the cathode and anode.
In my attempts to make a hydrogen producing cell (table salt used as the electrolyte in water) I've used two steel nails as both my cathode and anode. When I power it up, one side bubbles and ... |
> My question is this: Does electrolysis work the same way when the cathode and anode are made of the same metal? It might be a stupid question, but I can't find anything that answers this question specifically.
The battery or the power source does not care about the electrode material. Its job is to pump the electr... |
The evidence of a positively charged hydronium ion or a simple hydrogen ion comes indirectly from electrolysis experiments. This was demonstrated by Arrhenius more than hundred years ago. When he proposed these ideas during his PhD work, his mentors did not like these ideas which are bothering you now.
If we take ... |
Take this is an example:
$$\ce{HCl(aq) -> H^+(aq) + Cl^-(aq)}$$
and
$$\ce{HCl(aq) + H2O -> H3O+ + Cl^-(aq)}$$
Clearly the proton latches on to the water molecule but why? Also, why does the hydronium ion has an positive charge? Did the proton settle in the nucleus of the some atom?
What exactly is happe... |
Why does a proton react with water to form hydronium ion and why does that ion has an overall positive charge? |
Came across a few graphs that represent the mutual solubility of two compounds, for eg, solubility of KCl, and NaCl with H2O.
On these particular graphs, I can see Y axis as gms/100ml of KCl, on X axis it has gms/100ml of NaCL, and the graph has multiple lines each representing a curve at a specific temprature.
... |
We know that both $\ce{-CH=CH}_2$ and $\underbrace{\ce{-CH=CH-CH3}}_{1-propenyl}$ are electron withdrawing groups when attached to hydrocarbon chain.The question is which has greater electron withdrawing power?
The $\ce{-CH3}$ is electron donating hence $1$-propenyl should have lesser Electron withdrawing effe... |
I have about 200ml of methylated spirits and 500ml of 100% isopropyl alcohol that I want to mix together in a plastic drink bottle. I will use it for fuel in an alcohol burning stove while camping. I can't seem to find any other information about mixing them so...
1. Is it safe to do so?
2. Is a clear plastic dri... |
My teacher explained that free radicals could have a geometry that is planar or pyramidal(tending to tetrahedral) based on whether or not it is substituted by lone-pair containing atoms.
For example,
(CH3)3C would exhibit sp2 hybrid geometry of planar.
But when tri-substituted with Flourine/Chlorine, it will exh... |
Let me explain it in a less complicated and direct way.
H+ 'reacts' with H2O to form the hydronium because the oxygen in the water molecule has a lone pair of electrons that attracts the H+ ion.
Why does it have an overall positive charge? It is something you will be comfortable seeing in chemistry.
Right now yo... |
$\pu{50 g}$ of solid $\ce{NaOH}$ is added to $\pu{1.5 L}$ of $\pu{2.4 M}$ $\ce{NaOH}.$ Water is then added to the mix until the solution reaches $\pu{5 L}.$ I need to find molarity of the final solution.
I am a bit confused because I have different answers with my friends, my approach was as follows.
The molarit... |
I have a question about changing the functional after geometry optimization. I have done the geometry optimization with B3LYP functional, however, there is a need to calculate the excited state energy, so CAM-B3LYP functional should be a better suited for that. So do I need to reoptimize the geometry or are these funct... |
Can I change a DFT functional after geometry optimization? |
I have a question about changing the functional after geometry optimization. I have done the geometry optimization with B3LYP functional, however, there is a need to calculate the excited state energy, so CAM-B3LYP functional should be a better suited for that. So do I need to reoptimize the geometry to use CAM-B3LYP o... |
Is it safe to mix methylated spirits with isopropyl alcohol? |
My teacher explained that free radicals could have a geometry that is planar or pyramidal(tending to tetrahedral) based on whether or not it is substituted by lone-pair containing atoms.
For example,
$\ce{(CH3)_3C}$ would exhibit sp2 hybrid geometry of planar.
But when tri-substituted with Flourine/Chlorine, it ... |
Im reading Agre's paper on aquaporins and he uses a unit called "mosM" throughout the paper.
>Oocytes were transferred from 200 mosM to 70 mosM modified Barth's buffer
I just want to understand what this unit means, is it the same as mOsm? I know this might be an very stupid question but hey, I'm only a undergrad.
... |
What is the difference in mosM and mOsm units, if there is any at all? |
Im reading Agre's paper on aquaporins and he uses a unit called "mosM" throughout the paper.
>Oocytes were transferred from 200 mosM to 70 mosM modified Barth's buffer
I just want to understand what this unit means, is it the same as mOsm? I know this might be an very stupid question but hey, I'm only a undergrad.
... |
I think, the answer to number 1 will remove the need to answer the subsequent questions:
> 1\) Which method gives the true d-electron count?
**Neither!**
You *cannot*, and I want to stress that, derive the oxidation state of a metal in a complex solely by looking at its ligands. You can make educated guesses a... |
I'm reading Agre's paper on aquaporins \[[1](https://doi.org/10.1126/science.256.5055.385)\] and he uses a unit called "mosM" throughout the paper, for example:
> … ocytes were transferred from 200 mosM to 70 mosM modified Barth's buffer.
I just want to understand what this unit means, is it the same as mOsm? I ... |
We know that both ethenyl $\ce{-CH=CH}_2$ and allyl $\ce{-CH=CH-CH3}$ are electron-withdrawing groups when attached to hydrocarbon chain. Which one has greater electron withdrawing power?
The $\ce{-CH3}$ is electron-donating, hence allyl should have lesser electron withdrawing effect. Is this correct? |
We know that both ethenyl $\ce{-CH=CH}_2$ and 1-propenyl $\ce{-CH=CH-CH3}$ are electron-withdrawing groups when attached to hydrocarbon chain. Which one has greater electron withdrawing power?
The $\ce{-CH3}$ is electron-donating, hence allyl should have lesser electron withdrawing effect. Is this correct? |
I came across several examples (such as many benzene derivatives) of hydrocarbons having resonance that also seem to have a sharp odour. So, does resonance have an effect on smell? |
Can DFT functional be changed after geometry optimization? |
I have done the geometry optimization with the B3LYP functional, however, there is a need to calculate the excited state energy, so the CAM-B3LYP functional should be better suited for that. Do I need to reoptimize the geometry to use CAM-B3LYP or are these functionals simillar enough so no reoptimization is needed?
|
Is it rigorous enough to change a DFT functional after geometry optimization to calculate excited state properties? |
I am trying to make a simple scented shampoo and body soap for my own use and for Christmas gifts.
I statr with a base of 32 oz – (a bit under a kg) of a mild commercial castille soap (Dr. Bronner’s Peppermint) to which I have added modest amounts of essential oils ranging from 2 tablespoons (lavender) to a few ml (... |
When multiple sources give the content of an ingredient my an unqualified percentage, can I safely assume this is by weight? Or; it's not a wart |
I came up with a hypothetical equation of state, where one of the consequences is that $U=G$, where $U$ is the internal energy and $G$ is the Gibbs free energy. I wanted to ask the chemists, is there a fundamental problem with this? Are there any real systems where this could happen? Thank you for your time |
What is the implication of having the internal energy equal the Gibbs free energy? |
Check if you may skip using _elemental bromine_ as starting material altogether. An alternative approach may be running the bromination in a heterogenic, biphasic setup with the couple $\ce{NaBrO3/NaHSO3}$ in water (e.g., [1998JOrgChem6023][1], [2000OrgProcRes Dev.30][2]), or $\ce{NaBr}$ / sodium perborate (e.g., [199... |
Like when iron reacts with water there forms iron oxide and hydrogen but how'll we come to know which of three equation will be right equation for reaction?
$$\ce{Fe + H2O → FeO + H2}$$
$$\ce{2Fe + 3H2O → Fe2O3 + 3H2}$$
$$\ce{3Fe + 4H2O → Fe3O4 + 4H2}$$ |
When Iron reacts with any other species, how will we know that the reaction will be of Fe(II) or Fe(III) i.e. of ferrous or ferric? |
I learnt that ZnO has a hexagonal crystal system. I was expecting that cations or anions would occupy the lattice points in hcp while voids would be occupied by anions or cations respectively. But while googling the ZnO structure, I found this structure below which was confusing because of my notion about lattice point... |
Is the lattice point in ZnO crystal structure occupied by the molecule ZnO or the ion /ce{O^{2-}} or /ce{Zn^{2+}}? |
Is the lattice point in ZnO crystal structure occupied by the molecule ZnO or the ion O^2-/Zn^2+? |
As @Waylander mentioned in comments, more information is needed to guess A and B.
Since, in the question other products have not been mentioned, I am writing the answers for them with reasoning.
**1)** Since on reaction of D with soda lime gives benzene, which is a decarboxylating reaction, we guess that D should... |
In our textbook and on the internet, it's given that the formula for **diamminechloridonitrito-N-platinum(II)** is $\ce{[Pt(NH3)2Cl(NO2)]}$.
However, according to IUPAC, the ligands must be written in
*"alphabetical order according to the first symbol of their formulae"*.
So shouldn't the name for this compoun... |
What is the chemical formula of diamminechloridonitrito-n-platinum(II)? |
> $\ce{N2+}$ has $2$ $\pi$-bonds and a half sigma bond.
First of all, how can a "half" sigma bond exist? Usually when we encounter non integral bond orders, it is mostly because of resonance which creates partial $\ce{\pi-\pi}$ bonds and doesnt involve orbitals participating in sigma bond.
To understand this, I t... |
[![bromobenzene to 1‐bromo‐3‐methylbenzene][1]][1]
I started by taking $\ce{FeCl3}$ to reduce electron-giving capacity of $\ce{Br}.$ How to proceed?
[1]: https://i.stack.imgur.com/WIS6k.png |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/j6TGn.png
Does the double bond of N=N, C=O and lone pair of oxygen and nitrogen involved in the MO diagram? |
How to draw molecular orbital diagram for this compound? |
> Give a molecular structure-based explanation for the differences in the UV-Vis
spectra in **I** and **II**. Use detailed MO schemes for **A** and **B** for illustration. (12 marks)
>
> [![Methyl red protonation][1]][1]
Does the double bond of N=N, C=O and lone pair of oxygen and nitrogen involved in the MO diag... |
How to draw molecular orbital diagrams for protonated/deprotonated methyl red? |
> $\ce{N2+}$ has $2$ $\pi$-bonds and a half sigma bond.
First of all, how can a "half" sigma bond exist? Usually when we encounter non integral bond orders, it is mostly because of resonance which creates partial $\ce{\pi-\pi}$ bonds and doesnt involve orbitals participating in sigma bond.
To understand this, I t... |
Analogy: you have 5 bottles of coke 1 L each; what is the total volume?
The formula you shown $(E = hf)$ is derived for exactly *one* photon.
Now, since you have 50 billion of photons $(N = \pu{5.00e10}),$ guess what the total energy would be?
>! $$E_\mathrm{tot} = Nhf = (\pu{5.00E10})(\pu{6.63E-34 J s})(\pu{1.0... |
> First of all, how can a "half" sigma bond exist?
Usually, you expect double bonds to be shorter and stronger than the corresponding single bonds, and triple bonds even shorter and stronger. The OP already mentioned bond-orders of 1.5 that occur for conjugate double bond systems, and those have properties in betwee... |
> First of all, how can a "half" sigma bond exist?
Usually, you expect double bonds to be shorter and stronger than the corresponding single bonds, and triple bonds even shorter and stronger. The OP already mentioned bond-orders of 1.5 that occur for conjugate double bond systems, and those have properties in betwee... |
> First of all, how can a "half" sigma bond exist?
Usually, you expect double bonds to be shorter and stronger than the corresponding single bonds, and triple bonds even shorter and stronger. The OP already mentioned bond-orders of 1.5 that occur for conjugate double bond systems, and those have properties in betwee... |
**Short Answer**:
There is a limit to the maximum value of electron density $\rho_e(\vec{r})$.
**Long Answer**:
It is true that electrons repel each other, so as the electron density increases, the interelectronic repulsion also increases. This means that you can find high electron density only if the nucleus-... |
**Short Answer**:
There is a limit to the maximum value of electron density $\rho_e(\vec{r})$.
**Long Answer**:
It is true that electrons repel each other, so as the electron density increases, the interelectronic repulsion also increases. This means that you can find high electron density only if the nucleus-... |
It is known that lead levels in jewelry is a problem, especially for children (https://dtsc.ca.gov/toxics-in-products/lead-in-jewelry/). As a parent with jewelry-loving children I am aware that ingestion or inhalation of dust or any part of the jewelry will be toxic, while simply touching it would not be. However, seve... |
How does lead toxicity from jewelry happen vs. occupational exposure? |
Somehow, I am getting confused about this...
In the 'J=L+S' equation about total angular momentum, which of the four quantum numbers used to describe the electrons and their states is included in the 'L'?
And does the'J' include the first, principal quantum number? |
Is the 'Total orbital angular momentum operator' 'L' a combination of the second (azimuthal) and third (magnetic) numbers? |
Somehow, I am getting confused about this...
In the $J=L+S$ equation about total angular momentum, which of the four quantum numbers used to describe the electrons and their states is included in the $L$?
And does the $J$ include the first, principal quantum number? |
Is the quantum number $L$ a combination of the azimuthal and magnetic quantum numbers $(\ell, m_\ell)$? |
The values of $L$ come from the individual $\ell$ values, according to the Clebsch-Gordan series:
$$L = |\ell_1 - \ell_2|, \ldots , \ell_1 + \ell_2.$$
where the dots indicate all "in-between" values with a step size of 1. The values of $S$ come from the individual $s$ values, in a similar fashion. Note that it is... |
In Pericyclic reactions, it is shown that the terminal bonds rotate (conrotation or disrotation) to allow for allignment of the FMO's, thereby forming the sigma bond
[![Pericyclic bond formation][1]][1]
However, a detail that most of my textbooks and references miss out on is **how is the double bond rotating abo... |
How do bonds rotate in pericyclic reactions? |
I am doing a project in chemistry at the moment to build a rocket out of materials that can be easily bought and that react strongly to create thrust.
I was wondering if anyone knew a good chemical formula for my rocket fuel? I know lots of good fuels and reactants used in amateur rocketry however commercial fuels hav... |
[![bromobenzene to 1‐bromo‐3‐methylbenzene][1]][1]
I started by taking $\ce{FeCl3}$ to reduce electron-giving capacity of $\ce{Br}.$ How to proceed? Any hints...
[1]: https://i.stack.imgur.com/WIS6k.png |
[![bromobenzene to 1‐bromo‐3‐methylbenzene][1]][1]
I started by taking $\ce{FeCl3}$ to reduce electron-giving capacity of $\ce{Br}.$ How to proceed?
[1]: https://i.stack.imgur.com/WIS6k.png |
I have learnt that phosphorus and sulfur have valences 3, 5 and 2, 4, 6 respectively because of vacant d orbitals. But how? <br>
phosphorus' configuration is $\mathrm{[Ne]3s^23p^3}$. there are 3 unpaired electrons that can get paired with bonds, so 3 makes sense (similar to nitrogen) and a similar argument for 2 with ... |
Why do phosphorus and sulfur have variable valences? |
With only three basic particles making up atoms, and their interaction fairly well understood (we can even predict the chemical properties of elements we have not yet discovered) atoms seem to be like Lego bricks: only fitting together in a limited number of ways. So how come, in the age of super computers, we have not... |
Why don’t we have a list of all compounds yet? |
This is the question we did in class-
1000g of 1 molality sucrose solution in water is cooled to -3.534°c. What mass of ice would be seperated out at this temperature? (Kf of H2O= 1.86 K.mol^-1.kg)
We first found the lowering of freezing point (FP) at 1 molality concentration of sucrose which will be 1.86°c. Then... |
What happens to a solution below its freezing point? |
Can someone please explain to me what is the differences between ```Si(OH)4```, ```H4SiO4```, and ```SiO2:2H2O```? I am currently studying sandstone acidizing geochemical models and this question came to me. It seems that ```SiO2:2H2O``` and ```Si(OH)4``` are basically the same thing and are considered minerals that ma... |
After mixing Cobalt(II) Chloride hexahydrate with ammonium chloride a violet complex forms, what would be the complex formed?
It was the precursor for producing hexamine cobalt chloride so I didn't characterize it.
I expect many compounds like hexaqua cobalt chloride and pentamine aqua cobalt chlride or amine chloro... |
I have learnt that phosphorus and sulfur have valences 3, 5 and 2, 4, 6 respectively because of vacant d orbitals. But how?
Phosphorus' configuration is $\mathrm{[Ne]3s^23p^3}$. There are 3 unpaired electrons that can get paired with bonds, so 3 makes sense (similar to nitrogen) and a similar argument for 2 with sul... |
Just came across a specific type of art called Gyotaku where specific types of ink are used to paint over one side of a fish and then a paper (rice paper, shoji paper, ...) is placed on top in order to retrieve the fish impression.
As catching the fish just to print doesn't seem worthy, I am wondering if there there... |
Are there safe inks that allow one to eat a fish after painting it? |
I Googled "edible ink" and found [this](https://www.amazon.com/coloring-Gourmet-Decorating-Frosting-Edibleink/dp/B07HQZYSZ9/ref=sr_1_8?dchild=1&keywords=edible+ink&qid=1608341746&sr=8-8) item, which is a set of edible ink-containing pens.
The keyword is "edible." I'd stay away from anything not specifically labeled ... |
Ozone would be expensive, presumably, to use as an oxidizer instead of O2, but would the extra oomph be worth it?
Or does the 'regular' oxygen provide as much thrust/energy/heat as can be provided, given the liquid hydrogen propellant?
(I figured Chemistry was better than Physics, Engineering or Astronomy for thi... |
Why don't NASA or SpaceX rockets, etc. use ozone as an oxidizer for their fuels? |
Can someone please explain to me what is the differences between $\ce{Si(OH)4}$, $\ce{H4SiO4}$, and $\ce{SiO2.2H2O}$? I am currently studying sandstone acidizing geochemical models and this question came to me. It seems that $\ce{SiO2.2H2O}$ and $\ce{Si(OH)4}$ are basically the same thing and are considered minerals th... |
Cycloaddition reactions of the form [4+2] and [2+2] are always suprafacial, as the geometry is too constrained to allow for antarafacial interaction between the FMO's. However, **for cycloaddition of longer chains, say [6+6] cycloaddition, can the cycloaddition be antarafacial?**
Here's a small scheme I came up with... |
Can cycloaddition reactions be antarafacial? |
As you noted, there will be some definite energy losses, however I think it's important to keep in mind as well, that electrolysis is a slow process, like charging an electric car. You can speed it up by applying more current, but ultimately there is a theoretical limit before your electrodes are toast (I nearly experi... |
So, I was wondering, I have these molecules $O_{2}^{\ +}$, $O_{2}^{\ -}$, $O_{2}$ and $C_{2}^{\ +}$.
When I try to find their bond order and their magnetic nature I get this:
$O_{2}^{\ +}=\frac{1}{2}\left(10-5\right)=2.5$ - Paramagnetic
$O_{2}^{\ -}=\frac{1}{2}\left(10-7\right)=1.5$ - Paramagnetic
$O_{2}=\f... |
How can I know which molecule is more stable when bond order it's equal? |
First, my answer here is relevant: [What is chemical formula of Bauxite?][1], and also follow links inside.
Regarding your question specifically, there is not much difference. However, there are some conventions that come into play here.
The three formulae describe compounds that stoichiometrically have four atom... |
Just came across a specific type of art called Gyotaku where specific types of ink are used to paint over one side of a fish and then a paper (rice paper, shoji paper, ...) is placed on top in order to retrieve the fish impression. After the impression, the ink is removed with water.
As catching the fish just to pr... |
So, I was wondering, I have these molecules $\ce{O^+2}$, $\ce{O^-2}$, $\ce{O2}$ and $\ce{C^+2}$.
When I try to find their bond order and their magnetic nature I get this:
$\ce{O^+2} = \frac{1}{2} \left( 10 - 5 \right) = 2.5$ - Paramagnetic
$\ce{O^-2} = \frac{1}{2} \left( 10 - 7 \right) = 1.5$ - Paramagnetic
... |
According to IUPAC, the sequence of symbols within the coordination entity should be written in the following order:
1. The symbol of the **central metal atom** is written first.
2. The ***ligands*** are written afterwards and should be mentioned in *alphabetical order according to the first symbol of their formu... |
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