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Is there any difference between medical and cleaning ozone? |
Why doesn't $\ce{H4CO4}$ exist as a relatively stable compound? Its heavier homologue $\ce{H4SiO4}$ seems to exist although it is unstable to some extent but new methods have been able to stabilise orthosilicic acid using choline chloride. |
I was looking at the graphs for the density of air at different temperatures (link below) and I was wondering if air would not react with itself at high temperatures? I read that oxygen and nitrogen react at 1600 degrees Celsius, but even below that average temperature (because of the Maxwell Boltzmann distribution) I’... |
Is hydrogen bonding separate from permanent dipole interactions? What I mean here is that a molecule such as ethanol has hydrogen bonding, but does it also have permanent dipoles other than the ones on the oxygen and hydrogen atoms that c |
Is hydrogen bonding separate from permanent dipole interactions? |
Is hydrogen bonding separate from permanent dipole interactions? What I mean here is that a molecule such as ethanol has hydrogen bonding, but does it also have permanent dipoles other than the ones on the oxygen and hydrogen atoms that cause permanent dipole attraction? |
If we have a closed-shell atom or molecule (in the Born-Oppenheimer aproximation), and adopt the central field aproximation, we can write the ground state wave function of the system using a Slater determinant, constructed using the spin-orbitals that are the solutions of the equations
$$(h_{i} + V_{i}) \varphi_{i} ... |
Why I can't use a single Slater determinant to describe the ground state of open-shell atoms and molecules? |
The two molecules have very similar structures, but urea has a pKb of 13.9 while guanidine have a pKb of 0.4. If guanidine cation can be stabilized by resonance, then why can't urea cation do so? |
Why there is a huge difference between the basicity of urea and guanidine? |
The two molecules have very similar structures, but urea has a $\mathrm{p}K_\mathrm{b}$ of $13.9,$ while guanidine have a $\mathrm{p}K_\mathrm{b}$ of $0.4.$ If guanidine cation can be stabilized by resonance, then why can't urea cation do so? |
Now arsenic has been mentioned and interestingly, inorganic arsenic compounds interfere with the basic mechanism of DNA repair, which apparently increases frequency of chromosomal aberrations. So this is chemically predictable.
Cadmium has also been mentioned, but what is little known is "even tumor formation [52] c... |
You may have noticed that your question received a downvote. This was probably because you did not show any effort toward a solution of the question. I posted in a Comment some clues to assist you in a solution. In the interim an Answer was posted that showed the compounds formed in the reaction of acetone with H<sub>2... |
You may have noticed that your question received a downvote. This was probably because you did not show any effort toward a solution of the question. I posted in a Comment some clues to assist you in a solution. In the interim an Answer was posted that showed the compounds formed in the reaction of acetone with H<sub>2... |
Why is the Si-F bond the strongest single covalent bond of all? |
Why is the Si-F bond one of the strongest single covalent bonds of them all? |
What does ³D mean in energy level diagram for helium? |
It's common to read statements like:
>1. Tetrachloroethene ($\ce{CCl2=CCl2}$) was earlier used as a solvent for dry cleaning, but since it contaminated ground water and is a ***suspected*** carcinogen, it has been replaced by ... .
>2. Various hydrocarbons harms plant tissues, shed leaves, flowers and twigs.... |
> Show that the limiting fraction of association of a base in water, as
> the concentration of base approaches 0, is $\ce{\alpha=\frac{10^7 K_b}{(1+10^7*K_b)}}.$
I have tried this problem for a long time and have made little progress. Here is what I have tried:
We know that:
$\ce{K_b = \frac{[HB+]*[OH-]}{[B]}... |
> Show that the limiting fraction of association of a base in water, as
> the concentration of base approaches 0, is $$\alpha=\frac{10^7 K_b}{(1+10^7\times K_\mathrm{b})}.$$
I have tried this problem for a long time and have made little progress. Here is what I have tried:
We know that:
\begin{align}
K_\math... |
I'm currently using Clayden's organic chemistry textbook, and when he shows MO diagrams of functional groups of organic molecules, he sometimes treated it as if only orbitals on two atoms interacting. For example, the carbonyl chemistry is reduced to looking at the interaction between C and O orbitals. (For conjugated ... |
I'm currently using Clayden's organic chemistry textbook, and when he shows MO diagrams of functional groups of organic molecules, he sometimes treated it as if only orbitals on two atoms interacting. For example, the carbonyl chemistry is reduced to looking at the interaction between C and O orbitals. (For conjugated ... |
Believe it or not, the causative agent is the Ascorbic acid from the pineapples, which is known to cause pit corrosion (explained [here](https://www.substech.com/dokuwiki/doku.php?id=pitting_corrosion)) with stainless steel! Here is a [source](https://link.springer.com/article/10.1007/s12540-016-5684-7) to quote:
"A... |
I'm currently using Clayden's organic chemistry textbook, and when he shows MO diagrams of functional groups of organic molecules, he sometimes treated it as if only orbitals on two atoms are interacting. For example, the carbonyl chemistry is reduced to looking at the interaction between C and O orbitals. (For conjuga... |
Believe it or not, the causative agent is the Ascorbic acid from the pineapples, which is known to cause pit corrosion (explained [here](https://www.substech.com/dokuwiki/doku.php?id=pitting_corrosion)) with stainless steel! Here is a [source](https://link.springer.com/article/10.1007/s12540-016-5684-7) "Effect of asco... |
Believe it or not, the causative agent is the Ascorbic acid from the pineapples, which is known to cause pit corrosion (explained [here](https://www.substech.com/dokuwiki/doku.php?id=pitting_corrosion)) with stainless steel! Here is a [source](https://link.springer.com/article/10.1007/s12540-016-5684-7) "Effect of asco... |
Me and a friend were debating the following. In the elementary reaction $\ce{A + B -> A + C}$, my friend says that it is unimolecular because A does not "participate" in the reaction. So, he says that the rate law is $\ce{\text{rate} = k*[B]}$. But, I think that that since it is an elementary reaction step, you cannot ... |
If a reactant appears on both sides of an elementary equation, can it be cancelled? |
Believe it or not, the causative agent is the Ascorbic acid from the pineapples, which is known to cause pit corrosion (explained [here](https://www.substech.com/dokuwiki/doku.php?id=pitting_corrosion)) with stainless steel! Here is a [source](https://link.springer.com/article/10.1007/s12540-016-5684-7) "Effect of asco... |
Some dried, closed coconuts go through carbonation:
* The white meat of the coconut becomes disintegrated and smeary
* The liquid becomes carbonated with a bit sour-salty tasted coconut water (which reminds the taste of a water and baking soda solution) and a grey to blue color
* If the grey-blue liquid given en... |
Why dried, closed coconuts go through carbonation? |
Some dried, closed coconuts go through carbonation:
* The white meat of the coconut becomes disintegrated and smeary
* The liquid becomes carbonated with a bit sour-salty tasted coconut water (which reminds the taste of a water and baking soda solution) and a grey to blue color
* If the grey-blue liquid given en... |
So in a physics test question, there was this question when is Cp not Cv + R?
And I wrote: when number of molecules change. Because the derivation of above formula comes from nCp(dT) - nR(dT) = nCv(dT), depending on the variable conditions, ( for example under constant pressure, volume and temperature might change, ... |
So in a physics test question, there was this question when is Cp not Cv + R?
And I wrote: when number of molecules change. Because the derivation of above formula comes from nCp(dT) - nR(dT) = nCv(dT), depending on the variable conditions, ( for example under constant pressure, volume and temperature might change, ... |
I recently came across the statement
> The structure of crystalline $\ce{B2O3}$ consists of $\ce{BO4}$ tetrahedra, two sets of which form two types of interconnected spiral chains, three B-O bonds are equivalent, but the fourth one is somewhat longer.
Please explain the meaning of this statement and what's structur... |
Generally, heavier atoms means lower specific stored charge per mass.
Specific energy per mass depends of the cell redox systems, but also on the above.
Silicium, in contrary to carbon, does not form hexagonal planar structure with delocalized electrons like graphite, but prefers the diamond-like structure.
The Li-... |
So in a physics test question, there was this question when is $C_p$ not $C_V + R$?
And I wrote: when number of molecules change. Because the derivation of above formula comes from $nC_p\,\mathrm dT - nR\,\mathrm dT = nC_V\,\mathrm dT$, depending on the variable conditions, (for example under constant pressure, volu... |
This statement is relevant for the initially [incorrectly] determined structure of $\ce{B2O3}$ by Berger \[[1](https://doi.org/10.1107/S0365110X52001155), [2](https://doi.org/10.3891/acta.chem.scand.07-0611)\] who used powder x-ray diffraction data.
You can still access the structure and visualize it in 3D ([ICSD ... |
This statement is relevant for the initially [incorrectly] determined structure of $\ce{B2O3}$ by Berger \[[1](https://doi.org/10.1107/S0365110X52001155), [2](https://doi.org/10.3891/acta.chem.scand.07-0611)\] who used powder x-ray diffraction data.
You can still access the structure and visualize it in 3D ([ICSD 24... |
This statement is relevant for the initially [incorrectly] determined structure of $\ce{B2O3}$ by Berger \[[1](https://doi.org/10.1107/S0365110X52001155), [2](https://doi.org/10.3891/acta.chem.scand.07-0611)\] who used powder x-ray diffraction data.
You can still access the structure and visualize it in 3D ([ICSD 24... |
Me and a friend were debating the following. For the elementary reaction
$$\ce{A + B -> A + C}$$
my friend says that it is unimolecular because $\ce{A}$ does not "participate" in the reaction. So, he says that the rate law is
$$\text{rate} = k[\ce{B}].$$
But, I think that that since it is an elementary reac... |
Is it possible to put a substance with low volatility into a highly volatile solvent, thus make the original substance also vaporize quickly?
If not, are there anyway to increase it's volatility? |
How to increase volatility? |
This statement is relevant for the initially [incorrectly] determined structure of $\ce{B2O3}$ by Berger \[[1](https://doi.org/10.1107/S0365110X52001155), [2](https://doi.org/10.3891/acta.chem.scand.07-0611)\] who used powder x-ray diffraction data.
You can still access the structure and visualize it in 3D ([ICSD 24... |
Understand why phenol is more acidic than ethanol but is less reactive?
Eg: why unlike ethanol it can't react with a carboxylic acid? |
Why is phenol more acidic than an alocohol but less reactive as an alcohol? |
I understand why phenol is more acidic than ethanol but is less reactive?
Eg: why unlike ethanol it can't react with a carboxylic acid? |
Why is phenol more acidic than an alcohol but less reactive as an alcohol? |
What happens when you run house electricity (120VAC) through salt water? (with standard copper wires!)
Well, in https://youtu.be/dcrY59nGxBg , an interesting experiment was conducted to find out!
At the end of the video, however, the salt water became rather dark and murky, and I'm wondering what happened inside.
Di... |
What happens if you run house electricity through salt water? |
Consider the NMR of Brominated Pyridine shown below:
[![enter image description here][1]][1]
[![enter image description here][2]][2]
When I looked at the NMR data, I was confused because I thought that H2 would also be split in the meta position by H6 but the data says that this is not present in the overall... |
What happens when you run house electricity (120VAC) through salt water? (with standard copper wires!)
Well, in https://youtu.be/dcrY59nGxBg , an interesting experiment was conducted to find out!
At the end of the video, however, I noticed the salt water became rather dark and murky, and I'm wondering what happened i... |
What happens when you run house electricity (120VAC) through salt water? (with standard copper wires!)
Well, in https://youtu.be/dcrY59nGxBg , an interesting experiment was conducted to find out!
At the end of the video, however, I noticed the salt water became rather dark and murky, and I'm wondering what happened i... |
What happens when you run house electricity (120VAC) through salt water? (with standard copper wires!)
Well, in https://youtu.be/dcrY59nGxBg , an interesting experiment was conducted to find out!
At the end of the video, however, I noticed the salt water became rather dark and murky, and I'm wondering what happened i... |
What happens when you run house electricity through salt water? |
Does a bulky nuclephile react faster by Michael or direct addition? |
Following statement was given for boric acid $(\ce{H3BO3}):$
>At low concentrations $(\leq\pu{0.02 M})$ essentially $\ce{B(OH)3}$ and $\ce{B(OH)4-}$ are present, but at higher concentration the acidity increases and *pH studies are consistent with the formation of polymeric species such as* $$\ce{B(OH)3 <=> H+ + [B3O3... |
I just tried preparing calcium formate by adding Ca(OH)2 to ammonium formate, but I observed no bubble formation and no smell of ammonia. Why doesn't Ca(OH)2, being a strong base, displace ammonia? |
Following statement was given for boric acid $(\ce{H3BO3}):$
>At low concentrations $(\leq\pu{0.02 M})$ essentially $\ce{B(OH)3}$ and $\ce{B(OH)4-}$ are present, but at higher concentration the acidity increases and *pH studies are consistent with the formation of polymeric species such as* $$\ce{B(OH)3 <=> H+ + [B3O3... |
When referring to a particular atom, both in text and when using a graphical representation, several conventions are being applied.
In the field of crystallography an arabic numeral either follows the element symbol without any space, e.g. $\mathrm{C}42$ for carbon atom number $42$ (usually assigned during solve/ref... |
Is there a standardized way to assign a label to the symbol of a chemical element (in a published work)? |
You may have noticed that your question received a downvote. This was probably because you did not show any effort toward a solution of the question. I posted in a Comment some clues to assist you in a solution. In the interim an Answer was posted that showed the compounds formed in the reaction of acetone with H<sub>2... |
As instructed in Levine's Quantum Chemistry 7th edition, Chapter 13.8, page 377, for a $\pi \pi$ configuration of two nonequivalent electrons, four functions $\pi_{+1}(1) \pi_{-1}^{\prime}(2)$, $\pi_{+1}(2) \pi_{-1}^{\prime}(1)$, $\pi_{-1}(1) \pi^{\prime}_{+1}(2)$, $\pi_{-1}(2) \pi^{\prime}_{+1}(1)$
are used to const... |
How to understand the (non-)degeneracy of states of singlet $\Sigma$ and $\Delta$ terms for a $\pi\pi$ configuration of two nonequivalent electrons? |
I just tried preparing calcium formate by adding $\ce{Ca(OH)2}$ to ammonium formate, but I observed no bubble formation and no smell of ammonia. Why doesn't calcium hydroxide, being a strong base, displace ammonia? |
How to understand the (non-)degeneracy of states of singlet Σ and Δ terms for a ππ configuration of two nonequivalent electrons? |
By lithium aluminium hydride enolising the ketone, hydrogen gas is produced.
This is very entropically favourable, so why does this not happen and rather we get addition of the hydride ion to the carbonyl? |
Why does lithium aluminium hydride reduce a ketone over enolising the ketone? |
I wanted to ask a question about spin in an electron.
We were presented earlier today with the following information:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/FYrmU.png
Using my synoptic knowledge, I recall that spin up $\alpha$ had a value of $+\frac{1}{2}$ and spin down ... |
Suppose you dissolve $\ce{AgBr}$ in a $1$ litre solution of M molar $\ce{Na2S2O3}$. What is the solubility of $\ce{AgBr}$?
I am given that the $\beta_2$ of $\ce{Ag(S2O3)2^3-}$ is $2.8*10^{13}$, and the $\ce{Ksp}$ of $\ce{AgBr}$ is $5.4*10^{-13}$.
So, I have the equations:
$\ce{\frac{[Ag(S2O3)2^3-]}{[S2O3^2-]^... |
What am I assuming when I make this approximation? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/vKw2H.png
I've been stuck with this for some time. I just don't see it. As the reactant is Pd(0), I think oxidative addition will happen to the bromine. Then I would say an insertion reaction happens. However this would form a 7-membered r... |
What is the mechanism of this reaction? |
Could someone please illustrate how to determine the EZ configuration of this molecule? [![image below][1]][1]
What I understand so far is that if the two highest priority substituent on each side are on the same side, then it's Z and vice versa.
Now, how can I handle such a structure?
I've considered it and I... |
The problem is as follows:
> $5\,L$ of oxygen at $2\,atm$ of pressure and $10\,L$ of nitrogen at
> $4\,atm$ are collected in a vessel of $2\,L$ in capacity. Then $25\,L$
> of the mixture is released from the vessel at the pressure of
> $760\,mmHg$. Find the final pressure of the mixture if the temperature
> does... |
How to find the final pressure excerted by a mixture of gasses which are then released from a vessel after succesive fillings? |
**TL;DR**: In what aspects are the products of the indigo vat dyeing process (sodium sulphate, sulphite and thiosulphate ions) harmful to the environment or to living beings?
----------
I was recently looking into the wastewater created in the process of vat dying using indigo. I found out that since indigo i... |
Indigo and the Environment: is it that bad? |
This is a popular piece of confusion, because of a tersity in notation. Basically, we are secretly talking about *two* quantum numbers here: The total magnitude of the electron spin, $S$, and the relative orientation of the electron spins, $M_S$.
As you correctly identify, for the $\alpha\beta + \beta\alpha$ configu... |
This is a popular piece of confusion, because of a tersity in notation. Basically, we are secretly talking about *two* quantum numbers here: The total magnitude of the electron spin, $S$, and the relative orientation of the electron spins, $M_S$.
As you correctly identify, for the $\alpha\beta + \beta\alpha$ configu... |
What is the rate equation of this reaction with the presence of catalysts $\ce{MnO2}$, $\ce{PbO2}$ and $\ce{Fe2O3}$? (asking for each of them, separately, not altogether)
$$\ce{2H2O2 -> 2H2O + O2}$$ |
What is the rate equation of decomposition of $\ce{H2O2}$ with catalysts? |
You may have noticed that your question received a downvote. This was probably because you did not show any effort toward a solution of the question. I posted in a Comment some clues to assist you in a solution. In the interim an Answer was posted that showed the compounds formed in the reaction of acetone with H<sub>2... |
First, you got wrong thinking Michael addition is faster than the direct addition. Actually, Michael addition (thermodinamic control) is comparatively slower than the direct addition (kinetic control) here.
Second, to my understanding, Bürgi-Dunitz angle (Ref.1) has nothing to do here (may be it affect both addition... |
Could someone please illustrate how to determine the *E/Z* configuration of this molecule?
[![image below][1]][1]
What I understand so far is that if the two highest priority substituent on each side are on the same side, then it's *Z* and vice versa.
Now, how can I handle such a structure?
I've considered ... |
Could someone please illustrate how to determine the *E/Z* configuration of this molecule?
[![image below][1]][1]<br><br>
[![enter image description here][2]][2]
What I understand so far is that if the two highest priority substituent on each side are on the same side, then it's *Z* and vice versa.
Now, how ... |
I've got the following question in a workbook which I need to solve:
> A 50g sample of an experimental catalyst used in the polymerisation of
> butadiene is made up of 11.65g Co and 25.7g Cl. If the molar mass of
> the compound is 759g/mol, find the molecular formula of the catalyst.
I attempted to first find t... |
Believe it or not, the causative agent is the Ascorbic acid from the pineapples, which is known to cause pit corrosion (explained [here](https://www.substech.com/dokuwiki/doku.php?id=pitting_corrosion)) with stainless steel! Here is a [source](https://link.springer.com/article/10.1007/s12540-016-5684-7) "Effect of asco... |
What is the rate equation of this reaction with the presence of catalysts $\ce{MnO2}$, $\ce{PbO2}$ and $\ce{Fe2O3}$? (asking for each of them, separately, not altogether)
$$\ce{2H2O2 -> 2H2O + O2}$$ |
What is the rate equation of decomposition of H2O2 with catalysts? |
I've got the following question in a workbook which I need to solve:
> A 50g sample of an experimental catalyst used in the polymerisation of
> butadiene is made up of 11.65g Co and 25.7g Cl. If the molar mass of
> the compound is 759g/mol, find the molecular formula of the catalyst.
I attempted to first find t... |
As instructed in Levine's Quantum Chemistry 7th edition, Chapter 13.8, page 377, for a $\pi \pi$ configuration of two nonequivalent electrons, four functions $\pi_{+1}(1) \pi_{-1}^{\prime}(2)$, $\pi_{+1}(2) \pi_{-1}^{\prime}(1)$, $\pi_{-1}(1) \pi^{\prime}_{+1}(2)$, $\pi_{-1}(2) \pi^{\prime}_{+1}(1)$
are used to const... |
I've got the following question in a workbook which I need to solve:
> A $\pu{50g}$ sample of an experimental catalyst used in the polymerisation of butadiene is made up of $\pu{11.65g}$ of $\ce{Co}$ and $\pu{25.7g}$ of $\ce{Co}$. If the molar mass of the compound is $\pu{759 g/mol}$, find the molecular formula of t... |
Is there any aqueous solution (or simple method) to remove trace level of sulphur dioxide/nitrogen monoxide and nitrogen dioxide in a gas stream? |
> What is the pH when $0.025$ mol $\ce{NiCl2}$ is added to a $0.100$ M solution of $\ce{HCN}$, if the formation constant for $\ce{Ni(CN)4^2-}$ is $K_f=1.0*10^{22}$, and the $K_a$ for $\ce{HCN}$ is $4.9*10^{-10}$?
My approach is as follows:
1) $\ce{\frac{[H+][CN-]}{[HCN]}=4.9*10^{-10}}$
2) $\ce{\frac{[Ni(CN)4^{... |
![Diagram of P orbital vs. S orbital distance from nucleus][1]
My chemistry book explains that even though electrons in the $\mathrm{2p}$ orbital are closer to the nucleus on average, electrons from the $\mathrm{2s}$ orbital spend a very short time very close to the nucleus (penetration), so it has a lower energy.... |
I think your question implicates another question (which is also mentioned in some comments here), namely: Why are all energy eigenvalues of states with a different **angular momentum quantum number** $\ell$ but with the same **principal quantum number** $n$ (*e.g.*, $\mathrm{3s}$, $\mathrm{3p}$, $\mathrm{3d}$) degener... |
The $\mathrm{p}$ orbitals, for example, have a nodal plane where the nucleus is, which means the electron density is zero there.
An orbital doesn't represent a path the electrons take when moving. An orbital is a region of probability. To make things clear and definite, when we draw an orbital we only draw the regio... |
I'm looking at the melting temperature of metallic elements, and notice that the metals with high melting temperature are all grouped in some lower-left corner of the $\mathrm{d}$-block. If I take for example the periodic table with physical state indicated at $\pu{2165 K}$:
![enter image description here][1]
I s... |
While reading about the factors affecting the product of Friedel-Crafts Acylation with Acetyl Chloride, I came across a reaction involving Napthalene in two different solvents - In Nitrobenzene, substitution took place at the beta position, in Carbon Disulphide, substitution took place at the alpha position. What is th... |
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