instruction stringlengths 15 21.8k |
|---|
Can someone tell me how to draw the **β ** and **χ ** in **Materials Studio** or any other software? I've just started my project work, and I'm a beginner in this field.
I have searched for the **coordinates or .cif file** in the literature, but I could not find any. If anyone can provide me with those, it'll also b... |
How to get the coordinates or .cif file of β and χ ? |
Jiang <i>et al.</i> 2018 ([DOI: 10.1016/j.jechem.2018.01.026](https://doi.org/10.1016/j.jechem.2018.01.026)) may be relevant literature? Here's a quote:<br>
>These include three allotropes named borophene, beta-12(β12) and chi-3(χ3), which
have been successfully synthesized by physical methods [26,27].<br>... |
I was reading about borohydride reductions of aldehydes and ketones in one of the Clayden textbooks, and I saw that NaOH was used in the bottom reaction for some reason:
[![the bottom reaction uses sodium hyrdoxide][1]][1]
[1]: https://i.stack.imgur.com/x1480.png
Is this necessary? If so, then how? |
Does reduction of carbonyls using borohydride ever use NaOH in the reaction? |
I was studying nuclear Overhauser effect and came across this diagram$^1$:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/yvhGx.png
This diagram shows the energy levels of four possible nuclear spin states of **homonuclear** AX system. The white/grey boxes refer to population defici... |
Do the αβ and βα states of homonuclear AX system have same energy? |
In two containers we have Xenon. The volume of the first container is 2780 L, temperature is 300 degree Celsius, and n = 200 mol. Volume of the second container is 4000 L, temperature is 1300 degrees Celsius and n = 100 mol. Temperature in both of the containers is constant. How much Xe do we have to transfer from one ... |
Which of the following will react with dilute sulfuric acid? : copper, copper (II) oxide, copper (II) hydroxide, copper (II) carbonate.
**My answer:**
Metals react with acids to give salt and hydrogen. So, copper will react with dilute sulfuric acid.
Metal oxides act as base. So, they neutralise acid to give ... |
We are not trying to maximize overlap in this diagram, quite the opposite. You can imagine it rather as pushing negative charges, the negative ligands ions, unto the electrons on the central atom while looking at the orbital energies during this process. That is a repulsive interaction between two negative charges, tha... |
I am trying to implement a small python script to detect peaks and calculate the corresponding area. The y-values are in mAU and x-values in minutes but there are some unit conversions in most HPLC softwares. For example in this image (found [here](https://lab-training.com/2013/12/27/how-to-read-a-chromatogram/)):
[... |
First of all, I would like to mention that I am only talking about elements that aren't from the d or f blocks.
In order to further elaborate on my question, I would like to take the third period as an example.
[![Ionization energies of period 3.][1]][1]
[![Atomic radii of period 3.][2]][2]
[1]: ht... |
Why does the ionization enthalpy of elements across a period not follow a regular pattern while the atomic size always decreases? |
Height in HPLC simply refers to the height of the peak (= maximum value of the peak) above the baseline. The point by z1273 is right in the sense that this voltage to height conversion factor is instrument specific but this height cannot be in milliabsorbance units- it is too large for absorbance. This height is appare... |
I'm trying to mix my own fertilizer to grow some peppers.
Fertilizers are labeled with NPK ratios, so mixing two volumes and finding the result is easy - just multiply the concentration of each component by the ratio of the solution over the total volume. For example, 1L of a 3-4-6 solution plus 1L of a 5-2-6 solut... |
I'm trying to mix my own fertilizer to grow some peppers.
Fertilizers are labeled with NPK ratios, so mixing two volumes and finding the result is easy: Just multiply the concentration of each component by the ratio of the solution over the total volume. For example, $\pu{1L}$ of a $3:4:6$ solution plus $\pu{1L}$ o... |
This question concerns the dihalo addition reactions. I've learned that a halogen molecule (which, of course, consists of two atoms of the respective halogen) is more easily polarised by the double bond present in an alkene if it has a larger atomic number.
My question is this: Is this because the electrons of the h... |
Is the polarisation of halogens of higher atomic number easier because the electrons are further away from its core? |
If I have 10 mL 0.9% w/v $\ce{NaCl}$ solution, I can deduce that the solution contains 0.09 g of $\ce{NaCl}$.
Imagine that this is standard laboratory conditions and 1 ml = 1 g is acceptable.
Is the mass of $\ce{H2O}$ simply $\pu{10 g} - \pu{0.09g}$?
This would lead to mole fractions of $\pu{0.49}$% $\ce{H2O}$ ... |
Height in HPLC simply refers to the height of the peak (= maximum value of the peak) above the baseline. The point by z1273 is right in the sense that this voltage to height conversion factor is instrument specific but this height cannot be in milliabsorbance units- it is too large for absorbance. This height is appare... |
If I have 10 mL 0.9% w/v $\ce{NaCl}$ solution, I can deduce that the solution contains 0.09 g of $\ce{NaCl}$.
Imagine that this is standard laboratory conditions and 1 ml = 1 g is acceptable.
Is the mass of $\ce{H2O}$ simply $\pu{10 g} - \pu{0.09g}$?
This would lead to mole fractions of $\pu{76.43}$% $\ce{H2O}$... |
This answer just popped up when I searched for viscosity of water-ethanol mixtures, so I just copied the abstract:
Viscosities of Binary and Ternary Mixtures of Water, Alcohol, Acetone, and Hexane
https://www.tandfonline.com/doi/abs/10.1080/01932690802313006?journalCode=ldis20
"This articles studied and deter... |
I was reading about borohydride reductions of aldehydes and ketones in one of the Clayden textbooks, and I saw that NaOH was used in the bottom reaction for some reason:
[![the bottom reaction uses sodium hyrdoxide][1]][1]
[1]: https://i.stack.imgur.com/x1480.png
Is this really necessary? I know that usually w... |
If Carbon's sp2 orbital is overlapped with Hydrogen's s then why it is sp2 it why not sp2s?
Why it is not sp2s |
> I have calculated pressure in container one and that is p1 = 342817.92 Pa, and in container two p2 = 326979.2275 Pa. Then I have substracted this two values which gives me 15838.6925 Pa. After that I have divided this value with two, to figure out how much do I have to decrease pressure in container 1, and that gives... |
> I have calculated pressure in container one and that is p1 = 342817.92 Pa, and in container two p2 = 326979.2275 Pa. Then I have substracted this two values which gives me 15838.6925 Pa. After that I have divided this value with two, to figure out how much do I have to decrease pressure in container 1, and that gives... |
> I have calculated pressure in container one and that is p1 = 342817.92 Pa, and in container two p2 = 326979.2275 Pa. Then I have substracted this two values which gives me 15838.6925 Pa. After that I have divided this value with two, to figure out how much do I have to decrease pressure in container 1, and that gives... |
If carbon's $\mathrm{sp^2}$ orbital is overlapped with hydrogen's $\mathrm{s},$ then why it is $\mathrm{sp^2}$ and why not $\mathrm{sp^2s}?$ |
Why there is no sp2s hybridization in hydrocarbons? |
> I have calculated pressure in container one and that is p1 = 342817.92 Pa, and in container two p2 = 326979.2275 Pa. Then I have substracted this two values which gives me 15838.6925 Pa. After that I have divided this value with two, to figure out how much do I have to decrease pressure in container 1, and that gives... |
> I have calculated pressure in container one and that is p1 = 342817.92 Pa, and in container two p2 = 326979.2275 Pa. Then I have substracted this two values which gives me 15838.6925 Pa. After that I have divided this value with two, to figure out how much do I have to decrease pressure in container 1, and that gives... |
> I have calculated pressure in container one and that is p1 = 342817.92 Pa, and in container two p2 = 326979.2275 Pa. Then I have substracted this two values which gives me 15838.6925 Pa. After that I have divided this value with two, to figure out how much do I have to decrease pressure in container 1, and that gives... |
**THIS QUESTION HAS BEEN HEAVILY EDITED**
The original question was a bit too broad I believe, and was also based on a misconception.
As far as I know, the reason isoctane is better than octane in gasoline engines is because the octane is more prone to ignition by pressure. This makes it ignite when it is not su... |
I wonder, what happens when sodium reacts with alcohol? What is the reaction mechanism?
I think that sodium is an electrophile that attacks the nucleophile oxygen atom in the -OH-group of the alcohol. Sodium will take one electron and bond with the oxygen molecule, while the bond between the oxygen and hydrogen will... |
When two liquids mix, and they are not hindered by a polarity mismatch (like oil and water), why don't they always form a homogenous mixture? Due to entropy, a liquid will disperse itself evenly. This even distribution will lead to homogeneity, no? According to an answer to this question (one given when this question l... |
As far as I know, the reason isooctane is better than octane in gasoline engines is because the octane is more prone to ignition by pressure. This makes it ignite when it is not supposed to, which damages the engine.
Isooctane, however, is somehow less prone to this. Why is that? Why is isooctane "more resistant to ... |
Why is gasoline consisting of heavily branched alkanes better fuel than gasoline consisting of more linear alkanes? |
> I have calculated pressure in container one and that is p1 = 342817.92 Pa, and in container two p2 = 326979.2275 Pa. Then I have substracted this two values which gives me 15838.6925 Pa. After that I have divided this value with two, to figure out how much do I have to decrease pressure in container 1, and that gives... |
I have to an extent understood hyperconjugation but I don't understand why It only happens from an sp3 hybridised orbital bonded with hydrogen why doesn't it normally happen?
I've have just learnt hyper conjuncation so go easy on me
|
Let consider ratio of N/P.
Let fertilizer A has this ratio N/P=a.
Let fertilizer B has this ratio N/P=b.
Let you want the ratio c, where a < c < b.
Then you need to mix A : B in ratio $$\frac{ b - c}{c-a}$$
In the Central Europe with German scientific influence, it is called the "mixing cross rule".
... |
Let consider ratio of N/P.
Let fertilizer A has this ratio N/P=a.
Let fertilizer B has this ratio N/P=b.
Let you want the ratio c, where a < c < b.
Then you need to mix A : B in ratio $$\frac{ b - c}{c-a}$$
In the Central Europe with German scientific influence, it is called the "mixing cross rule".
... |
I am a high school student and I am a little confused in solubility product, My confusion is that when we talk of solubility of salts we say that suppose if any salt have solubility s it means that whatever concentration of it we add on it will dissolve it will be dissolved by only s concentration into the solution and... |
I have to an extent understood hyperconjugation but I don't understand why the donation can only occur from a $\mathrm{sp^3}$-hybridised orbital bonded with hydrogen? What about other bonding partners? |
Does hyperconjugation only arise from C–H bonds? |
I am a high school student and I am a little confused in solubility product.
My confusion is that when we talk of solubility of salts we say that suppose if any salt have solubility $s$ it means that whatever concentration of it we add on it will dissolve it will be dissolved by only $s$ concentration into the solut... |
When finding the stability order of resonationg structures of certain molecules.. there is some confusion since some structures satisfy certain factors and others satisfy certain other factors. I want to know which factor has more weight to it i.e.. which factor matters the most. Can someone give me a priority order of... |
When finding the stability order of resonationg structures of certain molecules.. there is some confusion since some structures satisfy certain factors and others satisfy certain other factors. I want to know which factor has more weight to it i.e.. which factor matters the most. Can someone give me a priority order of... |
> I was learning about voltaic cells and came across salt bridges. If the purpose of the salt bridge is only to move electrons from an electrolyte solution to the other, then why can I not use a wire?
If you connect the two electrodes with a wire, you will short-cut anything else connected to the cell. If you connec... |
> I was learning about voltaic cells and came across salt bridges. If the purpose of the salt bridge is only to move electrons from an electrolyte solution to the other, then why can I not use a wire?
If you connect the two electrodes with a wire, you will short-circuit anything else connected to the electrodes. If ... |
Can the nitrogen of an amide displace a primary chloride in a SN2 reaction in the presence of a strong base? |
Do organic molecules reduce the freezing point of water in the same way that inorganic salts do? I've recently been swimming in lakes with a high organic content (e.g. mostly tannins. There's a lake in this area called Tea Lake). I've got an infra-red thermometer and readings taken from the water at this time of yea... |
To get a freezing point depression of $−1.86° C$, the solution should be made by adding $1$ mole organic substance to $1$ liter water. And $1$ mole per liter is much. For glucose, it is $180g$ per liter. It is nearly a syrup. I doubt your lake has such a high concentration whatever the nature of the solute. For salts, ... |
Silicon dioxide has a huge variety of structures. Most of them are built up from connected $\ce{SiO4}$ units — the $\ce{O–Si–O}$ angle is $109.5°$, accordingly. The VB/hybridization approach to this tetrahedron would consequently assign $4\text{ }\mathrm{sp^3}$ orbitals to the silicon atom.
Now, the interesti... |
Silicon dioxide has a huge variety of structures. Most of them are built up from connected $\ce{SiO4}$ units — the $\ce{O–Si–O}$ angle is $109.5°$, accordingly. The VB/hybridization approach to this tetrahedron would consequently assign $4\text{ }\mathrm{sp^3}$ orbitals to the silicon atom.
Now, the interesti... |
Silicon dioxide has a huge variety of structures. Most of them are built up from connected $\ce{SiO4}$ units — the $\ce{O–Si–O}$ angle is $109.5°$, accordingly. The VB/hybridization approach to this tetrahedron would consequently assign $4\text{ }\mathrm{sp^3}$ orbitals to the silicon atom.
Now, the interesti... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
How does VB theory explain the Si-O-Si bond angles in SiO2? |
To get a freezing point depression of $\pu{−1.86 °C},$ the solution should be made by adding $\pu{1 mol}$ organic substance to $\pu{1 L}$ water. And $\pu{1 mol}$ per liter is much. For glucose, it is $\pu{180 g}$ per liter. It is nearly a syrup. I doubt your lake has such a high concentration whatever the nature of the... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
The modulus squared of the radial wave function gives the probability of finding an electron in an infinitesimal volume dv. On the other hand, the radial distribution gives the probability of finding an electron in a shell of radius r and thickness dr, or in other words, the probability of finding an electron at a radi... |
Why is the radial distribution at the nucleus 0 but not the radial wave function? |
We know that dissolution of sugar in water is a spontaneous process.
So, change in Gibbs Free Energy (ΔG) must be negative for the overall process.
ΔG = ΔH - TΔS < 0
Hence either the enthalpy or entropy must drive the reaction.
Now, after searching for the values, most websites suggest the process is endoth... |
We know that dissolution of sugar in water is a spontaneous process.
So, change in Gibbs free energy $(ΔG)$ must be negative for the overall process:
$$ΔG = ΔH - TΔS < 0$$
Hence either the enthalpy or entropy must drive the reaction.
Now, after searching for the values, most websites suggest the process is ... |
We know that dissolution of sugar in water is a spontaneous process.
So, change in Gibbs free energy $(ΔG)$ must be negative for the overall process:
$$ΔG = ΔH - TΔS < 0$$
Hence either the enthalpy or entropy must drive the reaction.
Now, after searching for the values, most websites suggest the process is ... |
I know that the s-orbitals of H atom are spherically symmetrical. But the p,d or f orbitals aren't. So, the H-atom needn't necessarily be spherically symmetrical, as the wave-function would be a linear combination of all the orbitals. But, in a certain hypothesis, if I assume the H-atom to be spherically symmetrical, w... |
For the wave function of $\mathrm{s}$ orbital $\psi(r)$, the radial propability is:
$P(r)=4\pi r^2 \cdot|\psi(r)|^2$.
So even if the differential probability $|\psi(r)|^2$ is nonzero for $r=0$, the integral probability over a spherical surface $P(r)$ in $r,r+\mathrm{d}r$ interval raises with $r^2$ and is zero f... |
I've learnt that water can dissolve ionic bonds because it possesses a high dielectric constant.
In the cases of covalent compounds (especially the non-polar covalent compounds), where the molecules are held together by mainly van der Waals forces of attraction. They are said to possess a higher dielectric constant... |
According to Bohr model of atom, [electrons move up an energy level in presence of EM field and emit a photon moving down the level][1].
In complete absence of any external EM field, shouldn't the electron collapse into the nucleus since it would keep losing energy as photons but wouldn't gain any?
[1]: http... |
For the wave function of $\mathrm{s}$ orbital $\psi(r)$, the radial propability is:
$P(r)=4\pi r^2 \cdot|\psi(r)|^2$.
So even if the differential probability $|\psi(r)|^2$ is nonzero for $r=0$, the integral probability over a spherical surface $P(r)$ in $r,r+\mathrm{d}r$ interval raises with $r^2$ and is zero f... |
According to Bohr model of atom, [electrons move up an energy level in presence of EM field and emit a photon moving down the level][1].
In complete absence of any external EM field, shouldn't the electron collapse into the nucleus since it would keep losing energy as photons but wouldn't gain any?
(I do know (a... |
I know ,in quantum mechanics it's important that the wavefunction has to be finite everywhere , including infinity. It's a criteria for acceptable wavefunction . What exactly does this statement mean ? And how it's associated with square integrability ?
[1]: https://i.stack.imgur.com/Piau9.jpg |
What's the meaning of wavefunction being finite? |
For the wave function of $\mathrm{s}$ orbital $\psi(r)$, the radial probability is:
$P(r)=4\pi r^2 \cdot|\psi(r)|^2$.
So even if the differential probability density $|\psi(r)|^2$ is nonzero for $r=0$, the integral probability over a spherical surface $P(r)$ in $r,r+\mathrm{d}r$ interval raises with $r^2$ and i... |
**How strong is the "hydrophobic force"?**\
\
Hydrophobic interactions are weak interactions but have a greater strength than hydrogen bonds. I find the strength of the hydrogen bond in literature to be near 1 pN. Finding the strength of the hydrophobic bond has proven to be a bit more elusive. I would guess that the... |
>[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/0oW5X.jpg
How to compare the melting points of the above isomers? I know that melting point depends upon the packing of the molecule, more efficient the packing, higher is the melting point. Symmetry in a compound also increases it's melt... |
I'm writing a paper rpg scenario, and even if we don't need to be 100% accurate about chemistry and physics in such games, one of my players has an advanced level in chemistry and I don't want him to cringe at the situation (and I can't ask him, obviously, or he'll be spoiled).
So, I need a river to be polluted wit... |
I started to make soap a few months ago and came up with a few formulas, one of it contains salicylic acid as a exfoliant/anti-acne agent, I've just realized that since salicylic acid is, well, an acid, and sodium hydroxide a base they will react together to form sodium salycilate, which doesn't have the required prope... |
How to mitigate salicylic acid saponification? |
So, I had a question on a chemistry test about two gas samples, one of O2 and one of N2, that had equal masses. We were given the time of effusion for the sample of N2 and then asked to calculate the time of effusion for O2. My initial reaction to the problem was to think that the nitrogen would effuse faster, as the e... |
Graham's Law of Effusion when Looking at Samples with Equal Mass? |
I have the following problem:
>The following reversible system is at equilibrium:
>$$\ce{P_{4(s)} + 6Cl_{2(g)} <=> 4PCl_{3(l)}} $$
>What happens with the equilibrium if $\ce{P_4}$ is added.
Normally, by applying _Le Chatelier's principle_ the equilibrium should be shifted to the right, however, for some reason ... |
One might consider [reaction-bonded silicon carbide](https://www.azom.com/amp/article.aspx?ArticleID=147), which is essentially a composite of silicon carbide and elemental silicon, sometimes also containing graphite for sealing applications. To make reaction-bonded silicon carbide, a porous part containing silicon ca... |
One might consider [reaction-bonded silicon carbide](https://www.azom.com/amp/article.aspx?ArticleID=147), which is essentially a composite of silicon carbide and elemental silicon, sometimes also containing graphite for sealing applications. To make reaction-bonded silicon carbide, a porous part containing silicon ca... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
I experimentally obtained the activation energy of a reaction to be approximately 101kJ/mol. I was then going to use the value for the activation energy to see how the number of particles with sufficient energy to undergo a successful reaction changes with temperature using the Maxwell-Boltzmann energy distribution. Ho... |
A sample from a cell culture has some IgG and this is to be purified using protein A chromatography. Based on the chromatography handbook from GE-Healthcare/Cytiva, the protein sample should have "physiological" pH and conductivities. This corresponds to a pH between 6-8, but it is not clear what the conductivity sould... |
Right conductivity of protein sample for Protein A purification of human IgG? |
>[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/0oW5X.jpg
How to compare the melting points of the above isomers? I know that melting point depends upon the packing of the molecule, more efficient the packing, higher is the melting point. Symmetry in a compound also increases it's melt... |
Is it true that the atomic orbitals of separate atoms already have directionality, which ensures the directionality of the valence bond?
[![enter image description here][1]][1]
Doesn't this contradict [Unsöld's theorem][2] that states the square of the total electron wavefunction for a filled or half-filled sub-s... |
Is it true that the atomic orbitals of separate atoms already have directionality, which ensures the directionality of the valence bond? Or another words, what is the real spatial distribution of the electron density in the atom, obtained in the one-electron approximation?
[![enter image description here][1]][1]
... |
I was reading the [Lab Manual](https://ncert.nic.in/pdf/publication/sciencelaboratorymanuals/classXI/chemistry/kelm207.pdf) for Chemistry prepared by the [NCERT](https://en.wikipedia.org/wiki/National_Council_of_Educational_Research_and_Training) . While going through the the test for Chloride ions (pg 88) I came acros... |
I'd like to melt alumina in a slow, controlled manner.
So I thought a graphite crucible with a tungsten wire wrapped around it for heating would be a good start. To reduce heat losses, I put that crucible inside an outer crucible.
Question 1 - can I get away with Al2O3 for the outer one, given that the radial temp... |
I have a small question concerning the stirring bars cleaning. I use mine in BOD test wastewater for 5 days and I want to clean them so my question is can I soak them overnight with sodium hypochlorite (Javel) or it can affect their magnetic ability or something? |
Which of the following can be a source of error in Spectrophotometry? Mark the wrong answer |
I have tried to research whether titanium piercings will tarnish if one submerges in sulfur hot springs. Will titanium piercings react to the sulfur water? |
Will a sulfur piercing tarnish if submerged in sulfur (hot spring) water? |
Every IUPAC Systematic name I have come across, I have understood up until now. This is Carminic Acid ($\ce{C22H20O13}$):
[![Carminic Acid][1]][1]
<sub>(source: [chemspider.com](https://www.chemspider.com/ImagesHandler.ashx?id=8430568&w=250&h=250))</sub>
This is the IUPAC Systematic Name for Carminic Acid:... |
From my textbook, it is stated that:
e.g. If we add a basic salt $\ce{NaF}$, it will fully dissociate to give $\ce{F-}$. Then if we add $\ce{HF}$, since it is a weak acid, the high concentration of $\ce{F-}$ already present in solution shifts the equilibrium to the left, hence fewer $\ce{H+}$ forms than expected so... |
**How strong is the "hydrophobic force"?**\
\
Hydrophobic interactions are weak interactions but have a greater strength than hydrogen bonds. I find the strength of the hydrogen bond in literature to be near 1 pN. Finding the strength of the hydrophobic bond has proven to be a bit more elusive. I would guess that the... |
Is every tetramer thought to be a dimer of dimers? Because even if every subunit is unique in structure, it could be a heterodimer of heterodimers? Or is the term "dimer of dimers" reserved for something more specific like symmetric tetramers? |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.