instruction stringlengths 15 21.8k |
|---|
I need some information of bonding energy.
I found that the bonding energy of $\ce{I2}$ is $\pu{151 kJ/mol}$ (https://www.chegg.com/homework-help/dimethyl-ether-ch3och3-ethanol-ch3ch2oh-constitutional-isome-chapter-9-problem-90p-solution-9781259631757-exc),
but I have some difficulty in searching the bonding energy o... |
Let $\frac{h}{\pi}=\frac{nh}{2\pi}$, therefore $n=2$.
So, $$E=\frac{-13.6}{4}=\pu{-3.4eV}$$
The answer is $\pu{-6.8eV}$. What’s wrong with my solution? (I think the issue is with the formula, yet I would like to confirm it) |
The angular momentum of electron in an excited H atom is $\frac{h}{\pi}$. The potential energy (PE) of electron is? |
> The angular momentum of electron in an excited H atom is $\frac{h}{\pi}$. The potential energy (PE) of electron is?
Let $\frac{h}{\pi}=\frac{nh}{2\pi}$, therefore $n=2$.
So, $$E=\frac{-13.6}{4}=\pu{-3.4eV}$$
The answer is $\pu{-6.8eV}$. What’s wrong with my solution? (I think the issue is with the formula, y... |
I'm trying to make a diagram of the Pncn space group.
Firstly, I know that this space group belongs to the orthorhombic system and derives from the point group (2/m 2/m 2/m).
Therefore, although the abbreviated notation does not appear, this spatial group also has binary axes (which may be normal or helical).
... |
>$\pu{1 L}$ of an aqueous solution of urea having density = $\pu{1.06 g/mL}$ is found to have $\Delta T_b$ (elevation in boiling point) = $\pu{0.5° C}$. If the temperature of this solution is increased to $\pu{101.5° C}$, then calculate the amount of water which must have vapourised by doing so. Kb (ebullioscopic const... |
I'm studying the article [Synthesis of ordered mesoporous phenanthrenequinone-carbon via π-π interaction-dependent vapor pressure for rechargeable batteries][1], in which authors explain some properties of the resultant composite of phenanthrenequinone (PQ) and ordered mesoporous carbon CMK-3 by the $\pi-\pi$ stacking ... |
Does ordered mesoporous carbon (for example, CMK-3) contain aromatic rings? |
While learning about Carbon and its Compounds in a class 10 coaching, I suggested a structure for some isomers.
It contained a connection of two consecutive carbons connected by double bonds. The teacher said that it can be counted as one, but is not a stable compound.
A recent research on C18 carbon carbon chain al... |
Silver vaporized in a propane oxygen flame condensed onto borosilicate glass is highly reactive to the flame atmosphere.
The silver coating seems to disappear in an oxidizing flame yet turns yellows and browns in a reducing flame.
The level of reduction and even the pressure in the gas line will dramatically change... |
Silver vaporized in a propane oxygen flame condensed onto borosilicate glass is highly reactive to the flame atmosphere.
The silver coating seems to disappear in an oxidizing flame yet turns yellows and browns in a reducing flame.
The level of reduction and even the pressure in the gas line will dramatically change... |
What is the formula of bleaching powder? |
I am a new student of molecular dynamics. I have started using GROMACS a month ago.
I have a small box of 8192 molecules each with 3 atoms. I froze the last molecule and ran the simulation. I even converted the `.trr` file from binary to `.gro` and checked that the last molecule indeed stayed in the same place.
... |
Some topics here have touched on this before (see [1][1], [2][2], [3][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 'reference' and 'configuration'. I'll try to explain below... |
Your problem seems to be with the terminology used in CI methods, so let me go through the different terms you mentioned:
- A **configuration** is a certain occupation of (molecular) orbitals. Mathematically configurations can be represented in 2 ways. The first one is the **Slater Determinant** (SD), an anti-symmet... |
I am a 11th/12th grade student studying orbital configurations. I have gone over this lesson and it says to always draw spin up first. However, it never says why. Is drawing down spins first incorrect? |
Why draw "up" arrows first when filling orbital diagrams? |
Why are there only 7 types of unit cells and 14 types of Bravais lattices?
I was reading about solid-state chemistry for the first time and this limitation made no sense to me.
I tried to do the math and realized that there could be many more possibilities. Usually, the standard unit cell is described on the basi... |
I understand how to calculate the degree of polymerisation normally, but in this question, the extra H and OH outside the bracketed monomer have thrown me off. Do I include their atomic masses in the overall Atomic mass for the degree of polymerisation or are they not part of the monomer chain and so not part of the ca... |
What is the structure of $\ce{FeSO4 \cdot NO}$ that is formed when $\ce{NO}$ is passed through ferrous sulfate solution? If it is a brown ring complex then why does the complex sphere break upon heating to yield $\ce{NO}$? In general, when do the complex spheres break? |
In Clayden, Greeves, Warren Organic Chemistry Second Edition Page 815, it states:
> In four- and three-membered rings, *cis* couplings are larger than *trans* ...
but I did not find an explanation for the statement. That being said, why is it true that *cis* coupling is larger than *trans* coupling in cyclopropa... |
Why is cis proton coupling larger than trans proton coupling in cyclopropanes? |
A neutral Atom is an atom with equal number of protons and electrons
which gives it the oxidation state of 0
If we know the force of attraction between the proton and electron is equal
and assuming that :
- one proton's positive charge attracts one electron.
- The "neutral" in a neutral atom means electrically n... |
What causes a neutral atom to attract more electrons? |
I need to compute extremely accurate single point energies using coupled clusters. The methods to be employed scale largely with the number of basis functions. A few basis functions may have a huge impact in the computational cost.
I planned assigning a 3$\zeta$ basis set to a central atom, and 2$\zeta$ for the surr... |
I have a question about the NAO method. In my understanding, the NAO analysis is a method of calculation to get occupancy of electrons in center of each atoms. In other words, the result of NAO-occupancy indicates the electron configuration about a... |
>Why can't the $\mathrm{t_{2g}}$ argument be used for $\ce{Mn}$ ?
Because the number of $\mathrm{t_{2g}}$ electrons is not changing upon going from $\ce{Mn^3+}$ to $\ce{Mn^2+}$. In both $\ce{Mn^2+}$ and $\ce{Mn^3+}$ there are 3 $\mathrm{t_{2g}}$ electrons. I think the point they are trying to make with $\ce{Cr^3+}... |
I need to compute extremely accurate single point energies using the coupled cluster method. The methods to be employed scale largely with the number of basis functions. A few basis functions may have a huge impact in the computational cost.
I planned assigning a 3$\zeta$ basis set to a central atom, and 2$\zeta$ fo... |
During method selection our purification chemists have options like NH4, TFA, Formic Acid. What's the point of choosing only between acid? Why not use the strongest that guarantees ionization?
And if the analyte is an acid, don't we want to have a base as a modifier? Otherwise how can we ionize it using ESP ionizati... |
Choosing LCMS modifier - why only acids? |
> Name the compound:
>
> [![Halogen-substituted ethane][1]][1]
How should I name $\ce{Br3C-CHCl2}$? Is it 1,1,1-tribromo-2,2-dichloroethane or 2,2,2-tribromo-1,1-dichloroethane?
[1]: https://i.stack.imgur.com/3zD88.png |
How to name the compound with the formula Br3C-CHCl2? |
During method selection our chromatographists have options like NH4, TFA, Formic Acid. What's the point of choosing only between acid? Why not use the strongest that guarantees ionization?
And if the analyte is an acid, don't we want to have a base as a modifier? Otherwise how can we ionize it using ESP ionization? |
Choosing LC-MS modifier - why only acids? |
Why is the following compound named as 4-bromo-2-methoxyphenol and not 4-bromo-6-methoxyphenol?
Shouldn't the substituents be numbered according to their alphabetical order?
[![Structure of 4-bromo-2-methoxyphenol][1]][1]
[1]: https://i.stack.imgur.com/6mWfit.jpg
|
How to decide whether to pick 4-Bromo-2-methoxyphenol or 4-bromo-6-methoxyphenol as the name for the compound? |
During method selection our chromatographists have options like NH4, TFA, Formic Acid. What's the point of choosing only between acid? Why not use the strongest that guarantees ionization? The sample contains small organic molecules.
And if the analyte is an acid, don't we want to have a base as a modifier? Otherwis... |
I was also told that ΔH(solution) = ΔH(hydration) - ΔH(lattice E).
However, for ΔH(solution) to be exothermic, it has to have a negative value <0.
Which means lattice energy is going to have to be greater than ΔH(hydration) to produce a negative value, based on the equation above.
Yet I am also told that hydration e... |
I was told that the more exothermic the solution, the more soluble the salt. Is this statement wrong? |
> Does that mean that I should disregard the statement "the more exothermic the solution, the more soluble the salt."?
No, based on the Gibbs free energy equation $$\Delta G = \Delta H -T \Delta S$$ and the condition that $\Delta G<0$ for spontaneous dissolution, if you assume $\Delta S$ is constant then the statem... |
According to thoughtco:
If fluorescent dyes weren't put in glow sticks, you wouldn't see any light at all. This is because the energy produced is usually invisible ultraviolet light. Fluorescent dyes may be added to light sticks to release colored light.
The dyes all have there own unique chemical structure, but ... |
What effect does the dye color have on the kinetics of a commercial lightstick? |
Why is the dipole moment of XeF$_6$ zero? |
How to calculate the relationship between the pressures of zinc, carbon monoxide, and carbon dioxide based on mole balance? |
How to decide whether to pick 4-bromo-2-methoxyphenol or 4-bromo-6-methoxyphenol as the name for the compound? |
I was also told that $$\Delta H(\text{solution}) = \Delta H(\text{hydration}) - \Delta H(\text{lattice E})$$
However, for $\Delta H(\text{solution})$ to be exothermic, it has to have a negative value <0. Which means lattice energy is going to have to be greater than $\Delta H(\text{solution})$ to produce a negative ... |
A neutral atom is an atom with an equal number of protons and electrons
which gives it the oxidation state of 0.
If we know the force of attraction between the proton and electron is equal
and assuming that:
- one proton's positive charge attracts one electron.
- The "neutral" in a neutral atom means electrica... |
When a proton attracts an electron, the electron doesn't magically suck out the charge of the proton. The proton's charge is still distributed in all directions. The reason why 1 proton on average can attract only 1 electron is because electrons push each other out.
Now let's first take H - it has 1 proton which att... |
When a proton attracts an electron, the electron doesn't magically suck out the charge of the proton. The proton's charge is still distributed in all directions. The reason why 1 proton on average can attract only 1 electron is because electrons push each other out.
Now let's first take H - it has 1 proton which att... |
When a proton attracts an electron, the electron doesn't magically suck out the charge of the proton. The proton's charge is still distributed in all directions. The reason why 1 proton on average can attract only 1 electron is because electrons push each other out.
Now let's first take H - it has 1 proton which att... |
The answer lies in **electronegativity**. When a proton attracts an electron, the electron doesn't magically suck out the charge of the proton. The proton's charge is still distributed in all directions. The reason why 1 proton on average can attract only 1 electron is because electrons push each other out.
Now let'... |
During method selection our chromatographists have options like NH4, TFA, Formic Acid. What's the point of choosing only between acid? Why not use the strongest that guarantees ionization? The sample contains small organic molecules.
And if the analyte is an acid, don't we want to have a base as a modifier? Otherwis... |
In general chemistry texts, the electron configurations are sometimes shown in boxes with up and down arrows to show the concept of paired spins. My impression for years was that Hund used such diagrams. However, flipping through his book *Linienspektren under Periodisches System der Elemente* which used the s,p, d, f ... |
Who came up with the box and arrow diagrams for electron configurations? |
I need to compute extremely accurate single point energies using the coupled cluster method. The methods to be employed scale largely with the number of basis functions. A few basis functions may have a huge impact in the computational cost.
I planned assigning a 3$\zeta$ basis set to a central atom, and 2$\zeta$ fo... |
Why is a alkyne anion more stable than a benzene anion? |
Gold nanoparticles have been used to make [ruby glass][1] for hundreds of years. The color is due primarily to [surface plasmons][2]. In a similar way, the color of metallic silver varies with particle size. If the particles are large, there is a large conduction band and the silver is highly reflective across the spec... |
For different chemical reactions, does the activation energy of that reaction directly relate to the reaction rate? In other words, would a reaction always be slower if it had a higher activation energy than another reaction?
Of course, one of the reactants will be kept constant and the other reactant will differ fo... |
Is activation energy directly related to the reaction rate? (keeping the temperature, concentration, catalyst, particle size and pressure constant) |
A neutral atom is an atom with an equal number of protons and electrons
We know the force of attraction between the proton and electron is equal
and assuming that:
- one proton's positive charge attracts one electron.
- The "neutral" in a neutral atom means electrically neutral.
How can a neutral atom attr... |
How can a neutral atom attract electrons when it's supposed have zero charge? |
I want to do a chemistry experiment, based on the reactions present in the bicarbonate buffer system. It needs to be heavily chemistry based, rather than biology based-- any suggestions preferably based on a factor other than pH for the independent variable (pH can be dependent variable)? Especially preferable if they... |
What chemistry lab experiements can I do based on the bicarbonate buffer system? |
HBr formation can be explained by simple orbital overlap as well as by sp3 hybridisation of Br. Can't we use dipole moment to find if the lone pairs on Br are mutually perpendicular or sp3 hypridised? |
Is Br sp3 hybridised in HBr? |
the correct IUPAC name of a compound was :
4-(1,1-dimethylethyl)-5-ethyloctane
my question is why not :
4-ethyl-5-(1,1-dimethylethyl)octane ?
are prefixes such as di tri etc considered for alphabetical order?
and what about prefixes such as cyclo, spiro are they too taken into consideration for ... |
is prefixes such as di tri etc considered for alphabetical order in IUPAC NOMENCLATURE? |
Why is molar mass of a substance and atomic mass number usually the same? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/82wDZ.jpg
according to me in the above compound, 8 pi electrons are present as there are 3 double bonds therefore
2 x 3 =6 pi electrons
and 2 pi electrons as one of the two lone pairs of oxygen will participate in resonance
... |
are all lone pairs considered as pi electrons? |
the question was how many ether metamers are possible for C4H10O . according to me, the answer should be 2 but it was given 3. I know 3 structures can be made ;
CH3—O—CH2—CH2—CH3
CH3—CH2—O—CH2—CH3
CH3—O—CH(CH3)2
structure 2 and 3 are metamers
but 1st and 3rd structures are positional isomers? then how ans ... |
are not 1st and 3rd structure positional isomer? |
This is the question I'm attempting:
In the definition of activation energy, it doesn't say of that is the minimum energy required for 1 mole of reactant or otherwise. Can anyone help me understand this? Thank you very much. |
Does the activation energy depend upon the stoichiometric coefficient? |
This is the question I'm attempting:
In the definition of activation energy, it doesn't say if that is the minimum energy required for 1 mole of reactant or otherwise. Can anyone help me understand this? Thank you very much. |
> For the decomposition of $\ce{N2O5(g)}$ it is given that
> $$
\begin{align}
\ce{2 N2O5(g) &→ 4 NO2(g) + O2(g)} &\quad\text{activation energy} &= E_\mathrm{a}\\
\ce{N2O5(g) &→ 2 NO2(g) + 1/2 O2(g)} &\quad\text{activation energy} &= E'_\mathrm{a}
\end{align}
$$
> then
> (**1**) $E_\mathrm{a} = 2E'_\mathrm... |
> How many ether metamers are possible for $\ce{C4H10O}?$
According to me, the answer should be 2 but it was given 3. I know 3 structures can be made:
$$\ce{CH3—O—CH2—CH2—CH3}\tag{1}$$
$$\ce{CH3—CH2—O—CH2—CH3}\tag{2}$$
$$\ce{CH3—O—CH(CH3)2}\tag{3}$$
Structure 2 and 3 are metamers, but 1st and 3rd structu... |
How many ether metamers are possible for C4H10O? |
[![2‐methylidene‐2H‐pyran][1]][1]
According to me, in methylenepyran 8 π-electrons are present as there are 3 double bonds. Therefore, 2 × 3 = 6 π-electrons and 2 π-electrons as one of the two lone pairs of oxygen will participate in resonance.
But the correct answer is 10 π-electrons. How? Are both lone pairs of... |
Are all lone pairs considered as π-electrons? |
$\ce{HBr}$ formation can be explained by simple orbital overlap as well as by $\mathrm{sp^3}$ hybridisation of $\ce{Br}.$ Can't we use dipole moment to find if the lone pairs on $\ce{Br}$ are mutually perpendicular or $\mathrm{sp^3}$-hybridised? |
Is Br sp³-hybridised in HBr? |
First of all, I'm not a chemist and my knowledge in chemistry is not that extensive. However, I would like ask the following question: are there any chemical reasons that would explain that mixing a blue ink with alcohol and MEG, lets say 3% as part of a volume of 1 L, gives a ways stronger blue than mixing in a big ta... |
I need to compute extremely accurate single point energies using the coupled cluster method. The methods to be employed scale largely with the number of basis functions. A few basis functions may have a huge impact in the computational cost.
I planned assigning a 3ζ basis set to a central atom, and 2ζ for ... |
Is it good practise to mix double and triple zeta basis sets? |
Does a T in a formula subscript indicate all possible numbers of atoms? $FeO_T$ is the specific one I came across, it seems to make sense in context but I've not done chemistry since school (tried googling already) so thought I'd better check. Thanks!
|
which has the highest enol content? |
A neutral atom is an atom with an equal number of protons and electrons
We know the force of attraction between the proton and electron is equal
and assuming that:
- one proton's positive charge attracts one electron.
- The "neutral" in a neutral atom means electrically neutral.
How can a neutral atom attr... |
How can a neutral atom attract electrons when it's supposed to have zero charge? |
Does a “T” in a formula subscript indicate all possible numbers of atoms? $\ce{FeO_T}$ is the specific one I came across (in the "bulk chemistry" table here: https://sciences.ucf.edu/class/simulant_lunarmare), it seems to make sense in context but I've not done chemistry since school (tried googling already) so thought... |
The $\ce{C18}$ allotrope cyclocarbon has been synthesized and imaged.<sup>\[1\]</sup> *Science* has most details behind a paywall, but [this](https://www.sciencenews.org/article/chemists-have-created-and-imaged-new-form-carbon) discussion includes an image:
[![ONE RING Scientists have created a new form of carbon c... |
Why does the image of cyclo[18]carbon look like a nonagon? |
In my understanding, the natural atomic orbital (NAO) analysis is a method of calculation to get occupancy of electrons in center of each atoms. In other words, the result of NAO-occupancy indicates the electron configuration about a non-bonded mol... |
Does the natural atomic orbital analysis result in natural electron configurations of molecules? |
The correct IUPAC name of a compound was: 4-(1,1-dimethylethyl)-5-ethyloctane.
my question is why not 4-ethyl-5-(1,1-dimethylethyl)octane?
Are prefixes such as di-, tri-, etc. considered for alphabetical order?
and what about prefixes such as cyclo, spiro? Are they too taken into consideration for alphabetical ... |
Is prefixes such as di-, tri-, etc. considered for alphabetical order in IUPAC nomenclature? |
Well, let's actually leave alone the separate question like from which "monomer" would one produce such a thing (can one actually consider it being a polymer? Or a covalent crystal?), because it seems like the most suitable candidate would be dicarbon.
All in all, might it be (under some conditions) energeticall... |
Is it possible to have an allotrope of carbon with formula $(=C=)_n$? |
I'm studying the article [Synthesis of ordered mesoporous phenanthrenequinone-carbon via π-π interaction-dependent vapor pressure for rechargeable batteries][1], in which authors explain some properties of the resultant composite of phenanthrenequinone (PQ) and ordered mesoporous carbon CMK-3 by the $\pi-\pi$ stacking ... |
In my understanding, the natural atomic orbital (NAO) analysis is a method of calculation to get occupancy of electrons in center of each atoms. In other words, the result of NAO-occupancy indicates the electron configuration about a non-bonded molecule. More specifically, electrons are rearranged in each atom acco... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.