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I was just searching whether Uracil is aromatic or not and in this [link](https://pubs.acs.org/doi/10.1021/jp404938u#:~:text=It%20was%20found%20that%20uracil,character%20in%20the%20gaseous%20phase.) it is said that:
> It was found that uracil possesses 30.0% of aromatic character in the gaseous phase.
What is th... |
Aromatic Character in Percentage? |
I am computing Franck-Condon Factors between the neutral ground state and cationic states to simulate the photoelectron spectra (using Gaussian 16, freq=FCHT). The target cationic state is a pi state and has 3/2 and 1/2 spin-orbit components. I have done optimization and frequency calculation for the pi state in TDDFT.... |
How to compute Franck-Condon Factors for spin-orbit states? |
[![enter image description here][1]][1]
The compound above is heated. CO2 is lost.
Why is compound A (below) formed and not the one below it?
Compound A:
[![enter image description here][2]][2]
Alternative compound I though would be correct:
[![enter image description here][3]][3]
In other words... |
2‐Cyano‐2‐cyclohexylideneacetic acid (**1**) is heated and $\ce{CO2}$ is lost:
[![2‐cyano‐2‐cyclohexylideneacetic acid to 2‐(cyclohex‐1‐en‐1‐yl)acetonitrile][1]][1]
Why is 2‐(cyclohex‐1‐en‐1‐yl)acetonitrile (**2**) formed and not 2‐cyclohexylideneacetonitrile (**3**)?
[![2‐cyclohexylideneacetonitrile][2]][2]
... |
I see no difference between the two. Both say that the degree of adsorption reaches a limiting value at high pressures and at very low pressures degree of adsorption is directly proportional to the pressure.
Where does the difference lie? |
How is Langmuir adsorption isotherm different from Freundlich's? |
Especially in high school/first-year undergraduate chemistry courses, we learn with great dedication the periodicities along groups and periods. There are various useful and interesting trends.
I wanted, however, to find the theoretical framework behind it which explains the trends through mathematical analyses. I s... |
I have a hopefully simple question. I am a tutor working with a student that wants to know where to find the most recent accurate measurements for elemental properties. He's only in Chemistry I, so he's not looking for every property out there calculated multiple ways. I think he (and I) just like looking at the best s... |
You should teach your student not to use numerical values with as many significant figures as possible. Knowing how to make sense to decimals is part of the scientific culture. The distance between two cities cannot be given to the least micrometer : it has no meaning. The weight of an object has no use if it is given ... |
So in the Finkelstein reaction, the iodide ion is supposed to replace another halogen(say chlorine) through SN2 mechanism.
But here, Acetone is used, which is a polar aprotic solvent. And in acetone, iodide ion is the weakest nucleophile. So how can it replace the chlorine?
Aren't we better off if we use water or e... |
I have searched a quite few sources on mechanism for Sandmeyer's reaction, but couldn't find (and understand) how CuCl for example helps in replacement of N2 from Benzene diazonium chloride and gives Chlorobenzene? In Solomon-Fryhle-Snyder's regarding the mechanism its been given that "*the mechanisms of these replacem... |
How exactly do Copper salts help in Sandmeyer Reaction (Halogenation)? |
2‐Cyano‐2‐cyclohexylideneacetic acid (**1**) is heated and $\ce{CO2}$ is lost:
[![enter image description here][2]
Why is this not formed?
[![2‐cyclohexylideneacetonitrile][3]][3]
In other words, why do π-electrons move into the ring?
[1]: https://i.stack.imgur.com/dHGzN.png
[2]: https://i.stack.... |
I have a compound named 7-(2,4-dimethyl)hexyl-3-ethyl-5,9,11-trimethyltridecane. I have a few questions:
1) why is it (2,4-dimethyl)hexyl and not (2,4-dimethylhexyl)? I asked this question because I saw a compound named 2,5-dimethyl-4-(2-methylpropyl)heptane, and not 2,5-dimethyl-4-(2-methyl)propylheptane.
2) why is ... |
[![enter image description here][1]][1]
Now at A, there is pressure by mercury column which is nothing but it's weight. Then, at C there is pressure which is atmospheric pressure. Also, the density at A is more than at C. What they say according to the law is that the pressure at C and A are same. I am not able to un... |
For a piece of coursework I am doing, I need to calculate the atomic packing factor of some ionic compounds. I have had no formal teaching in this area, so what I know comes from information I have found on the internet.
I take that the atomic packing factor is given by:
$$
APF = \frac{V_{atoms}}{V_{unit cell}}
$... |
How to find the atomic packing factor of Sodium Chloride (and other FCC ionic compounds in general)? |
This is actually an active area of research for [water clusters](http://en.wikipedia.org/wiki/Water_cluster). In principle, for $\ce{(H2O)_{n}}$ there should be a "melting" phase transition, much like for ice to liquid water.
So, in principle, if you had an accurate enough theoretical method, you could do molecular ... |
In which conditions the corrosion rate of aluminium is faster?
a) acidic conditions
b) neutral
c) alkaline conditions
I know that corrosion can be in a and c cases but I dont know when it'll be faster. Also please describe why corrosion rate in one case is faster than in other one. |
Said by other words, you do not believe that $3 + 2 = 3 + 2$
- There are 2 $\ce{Hg}$ columns, sharing the same pressure at the bottom.
- Both have the same height, so the pressure difference is the same.
- Yet you have doubts the pressures at their tops are the same.
> Pressure at A = Pressure at B +pgh
... |
As I understand; the reason we have smoke in a fire is because the heat causes wood (or whatever material is burning) to dis-integrate, the disintegrated components react with oxygen to create more heat; causing a chain reaction.
Much of the smoke we see is the dis-integrated carbon in the air from incomplete combus... |
Why does charcoal not produce smoke when heated? |
Is anyone able to explain why species 'D' is not included in the steady state approximation derivation for this E1cB reaction?
The correct rate equation in the image has been derived first and then I have added in the line I am confused about below
Thanks!
[![enter image description here][1]][1]
[1]: ht... |
Can the formation of the covalent bond in HCl be explained through the hybridization model?
We know for sure that it can be explained by the theory of molecular orbitals. In this way, it would be normal for the atomic orbital $s$ of the hydrogen to mix with one of the chlorine's atomic orbitals which has t... |
Said by other words, you do not believe that $3 + 2 = 3 + 2$
- There are 2 $\ce{Hg}$ columns, sharing the same pressure at the bottom.
- Both have the same height, so the pressure difference is the same.
- Yet you have doubts the pressures at their tops are the same.
> Pressure at A = Pressure at B +pgh
... |
In general, corrosion rate **depends** on too many factors. Which acid or base, which concentration, which temperature? Which other chemical species are present? Is there [galvanic corrosion](https://en.wikipedia.org/wiki/Galvanic_corrosion) present? Is there a voltage applied, and which voltage? And so on.
How do y... |
Said by other words, you do not believe that $3 + 2 = 3 + 2$
- There are 2 $\ce{Hg}$ columns, sharing the same pressure at the bottom.
- Both have the same height, so the pressure difference is the same.
- Yet you have doubts the pressures at their tops are the same.
> Pressure at A = Pressure at B +pgh
... |
Although this is an old question with an accepted answer, I think it's worth providing a second perspective rather than continuing extended discussion in the comments.
First off, let's consider the purpose of even considering hybridization. The purpose of constructing hydrid orbitals is to create localized bondin... |
How do strong acids conduct electricity in water?
I have just studied ionization of water and I'm confused about some points.
First: I know that water ionizes in a very small amount (10^-14) so it doesn't conduct electricity and if we add strong acid (or base) to it , it becomes a good conductor of electricity. My q... |
How does strong acids conduct electricity in water? |
Can the formation of the covalent bond in HCl be explained through the hybridization model?
We know for sure that it can be explained by the theory of molecular orbitals. In this way, it would be normal for the atomic orbital $s$ of the hydrogen to mix with one of the chlorine's atomic orbitals which has t... |
[![enter image description here][1]][1]
Now at A, there is pressure by mercury column which is nothing but it's weight. Then, at C there is pressure which is atmospheric pressure. Also, the density at A is more than at C. What they say according to the law is that the pressure at C and A are same. I am not able to un... |
Can the formation of the covalent bond in HCl be explained through the hybridization model?
We know for sure that it can be explained by the theory of molecular orbitals. In this way, it would be normal for the atomic orbital $s$ of the hydrogen to mix with one of the chlorine's atomic orbitals which has t... |
Often I see "Sodium Deoxycholate, ≥97% (**titration**)" offers. Is there any publicly available titration protocol I can use to confirm that statement? |
Although this is an old question with an accepted answer, I think it's worth providing a second perspective rather than continuing extended discussion in the comments.
First off, let's consider the purpose of even considering hybridization. The purpose of constructing hydrid orbitals is to create localized bondin... |
What is the easiest way to create a precipitation reaction at home, preferably with easily retrievable chemicals?
I need this because I'm making a video for my film education. |
What is the simplest way to create a precipitation reaction at home? |
According to the images below, the NH3+ on the side chain of lysine is less acidic than the NH3+ closer to the COO-. Why is this? Wouldn't the NH3+ have an intramolecular H-bond with a negatively charged oxygen on the carboxylic acid group, stabilizing it?
One possible explanation I thought of is the carbons on the ... |
Why is the side chain of lysine more basic? |
What we call "Hybridization" is really just a mathematical transformation of an approximated wavefunction. Your basic summation formula describes how to build some sort of customized wavefunction by forming a linear combination of some set of "basis" orbitals; you will find this equation over and over if you look up "b... |
I am currently teaching a course on groups, and want to give my students "real life" examples of symmetry groups to think about. The ethane molecule would be one such. But, the on-line sources don't all agree on the exact shape. I'm fairly sure ethane looks like either this
[![enter image description here][1]][1]
... |
What is the 3D shape of an ethane molecule? |
I am currently teaching a course on groups, and want to give my students "real life" examples of symmetry groups to think about. The ethane molecule would be one such. But, the on-line sources don't all agree on the exact shape. I'm fairly sure ethane looks like either this
[![enter image description here][1]][1]
... |
there is a reaction that confused me a bit:
[![enter image description here][1]][1]
According to my research on SeCl$_4$, it can be used as a dichlorinating agent for alkenes. However, I am totally confused about the mechanism. I've read about several mechanisms using PhSeSePh as a precatalyst but in this react... |
Reaction of SeCl4 with alkene and possible consecutive reaction? |
I used sandpaper of different grits to sand the surface of plastic. The surface is smooth but it looks dull after sanding. I read that one could use toothpaste to remove the foggy look but it did not work. I also tried vinegar with baking soda. When the plastic was inside the vinegar+baking soda bath, it looked transpa... |
How to make foggy and cloudy plastic fully transparent? |
I used sandpaper of different grits to sand the surface of plastic. The surface is smooth but it looks dull after sanding. I read that one could use toothpaste to remove the foggy look but it did not work. I also tried vinegar with baking soda. When the plastic was inside the vinegar+baking soda bath, it looked transpa... |
I came across an [_example_](https://i.stack.imgur.com/UhJZ0.png "O.P. Tandon's G.R.B Organic Chemistry - excerpt pg.122") today while I was studying tautomerism.
>It is an example of tautomerism exhibited by acetylactone/**1,3-diketone**; given under the **keto-enol systems under 1-3 migration/triad systems.** *(... |
Which enol form is more stable? |
TLDR: Do uric acid crystals in concrete make it hygroscopic enough to absorb moisture from the air so much that a spot of humidity is visible? Are uric acid crystals moisture-absorbent?
Here is the story:
In my parents' house, there is a mystery that we were unable to solve.
During the renovation, certain spots ... |
Does urine make concrete hygroscopic? |
I came across an [_example_](https://i.stack.imgur.com/UhJZ0.png "O.P. Tandon's G.R.B Organic Chemistry - excerpt pg.122") today while I was studying tautomerism.
>It is an example of tautomerism exhibited by acetylactone/**1,3-diketone**; given under the **keto-enol systems under 1-3 migration/triad systems.** *(... |
TLDR: Does urine make concrete hygroscopic enough to absorb moisture from the air so much that a spot of humidity is visible? Are uric acid crystals moisture-absorbent? (Urea apparently is according to Wikipedia)
Here is the story:
In my parents' house, there is a mystery that we were unable to solve.
During the... |
**strong text**Just looking around at the reactivity of aluminum, and wondered:
> Is if possible to reduce aluminum hydroxide to aluminum metal, by using a sacrificial magnesium electrode in a single displacement reaction?
I checked my revision of redox charts and it looks like it should work.
For more detail,... |
Is it possible to reduce aluminum hydroxide to aluminum metal by using a sacrificial magnesium electrode in a single displacement reaction?
I checked my revision of redox charts and it looks like it should work.
For more detail, consider: $\ce{Al}$ is very fond of bonding with oxygen. It's such a strong reaction ... |
[![4-bromo-1-tert-butyl-2-methylcycloheptane molecule][1]][1]
[1]: https://i.stack.imgur.com/IEzjz.jpg
So I'm having a hard tiem understanding why the numbering for this molecule goes: 4-bromo-1-tert-butyl-2-methylcycloheptane, instead of: 1-bromo-4-tert-butyl-3methylcycloheptane. Is it just because the overall... |
What is the correct numbering & order for this molecule? |
Should the molecularity be equal or less than the reaction order?
-if the answer is yes,
then, consider the reaction between H2 and I2 to produce HI.
the reaction equation as follows
- H2(g) + I2(g) → 2 HI(g)
If we consider the mechanism of this reaction
- I2(g)=2I(g) (equilibrium reaction)
- 2I(g)+H2(... |
Should the molecularity be equal or less than the reaction order?
Consider the reaction between $\ce{H2}$ and $\ce{I2}$ to produce $\ce{HI}:$
$$\ce{H2(g) + I2(g) → 2 HI(g)}$$
If we consider the mechanism of this multi-step reaction, the molecularity is 3 (*termolecular reaction*):
$$
\begin{align}
\ce{I2... |
Should the molecularity be equal or less than the reaction order?
Consider the reaction:
$$\ce{H2(g) + I2(g) → 2 HI(g)}$$
If we consider the mechanism of this multi-step reaction, the molecularity is 3 (*termolecular reaction*):
$$
\begin{align}
\ce{I2(g) &<=> 2I(g)} &\quad&\text{(equilibrium reaction)} ... |
Which subshell is more closer to the nucleus.4f or 6s?
6s gets filled first so does it have to be more closer to the nucleus? |
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... |
>Volume percentage (V/V): Solutions that are formulated from two liquids are often expressed as volume percent
with respect to the solute. The volume percent is the volume of a liquid in 100 mL of solution. The label on a bottle
of ordinary rubbing alcohol reads “isopropyl alcohol, 70% by volume”. Such a solution cou... |
Why can't we use 30 mL of water and 70 mL of ethanol to make a 70% (v/v) solution of Isopropyl Alcohol? |
Why can't we use 30 mL of water and 70 mL of alcohol to make a 70% (v/v) solution of Isopropyl Alcohol? |
Very interesting question - and thorough. But I would like to get proof that the spot is due to moisture. #1 Does the spot grow and shrink dependent on the relative humidity at that position? #2 If the spot is misted with a water sprayer, is it sharply defined? #3 If the spot is gently warmed with a space heater, does ... |
I'm a beginner of ChemDraw.
I'd like to draw a molecule from SMILES, but the ring bond should be drawn like the left image:
[![enter image description here][1]][1]
In my case, my image is drawn like the right image.
Is there any method to change the default style setting of it?
Thank you
[1]: https:... |
I'm a beginner at ChemDraw.
I'd like to draw a molecule from SMILES, but the ring bond should be drawn like the left image:
[![enter image description here][1]][1]
In my case, my image is drawn like the right image.
Is there any method to change the default style setting?
Thank you
[1]: https://i.st... |
I'm a beginner at ChemDraw.
I'd like to draw a molecule from SMILES and the ring bond should be drawn like the left image:
[![enter image description here][1]][1]
In my case, my image is drawn like the right image.
Is there any method to change the default style setting?
Thank you
[1]: https://i.sta... |
I'm a beginner at ChemDraw.
I'd like to draw a molecule from SMILES and the ring bond should be drawn like the left image:
[![enter image description here][1]][1]
In my case, my image is drawn like the right image.
Is there any method to change the default style setting?
[1]: https://i.stack.imgur.co... |
Firstly, how is $NaOH$ created? My teacher said that before it is $NaOH$, it is $NaO^-$.
$$NaO^- + H_2O = NaOH + OH^-$$
If so, that means that $NaO^-$ is a base, which would make $NaOH$ it's conjugate acid. However, $NaOH$ is a base. So, perhaps my teacher said wrong, and the fact is, the "prelude" to $NaOH$ is ... |
How is NaOH a base? |
I'm working on a chemical design project where zeolite crystals containing $\ce{Na+}$ cations is ion-exchanged via an aqueous solution of $\ce{AgNO3}$, $\ce{Cu(NO3)2}$, and $\ce{Zn(NO3)2}$, also containing $\ce{HNO3}$. The solid product now containing $\ce{Ag+}$, $\ce{Cu^2+}$, and $\ce{Zn^2+}$ cations is removed from t... |
Pure water does not conduct electricity.
When you dissolve a salt like $\ce{Na2SO4}$ in water the solution becomes a better conductor.
If electrolysis is done on this solution, oxygen and hydrogen gases form at the electrodes.
The ions $\ce{Na+}$ and $\ce{SO^{2-}4}$ don't seem to be doing anything further.
The el... |
How do strong acids conduct electricity in water?
I have just studied ionization of water and I'm confused about some points.
First: I know that water ionizes in a very small amount ($10^{-14}$) so it doesn't conduct electricity and if we add strong acid (or base) to it , it becomes a good conductor of electricity... |
> We take 10mL of $H_2SO_4$ with a $96\%$ of mass and density $1.84g/cm^3$, and we add it into a flask that has $0.5L$ of capacity, filled up to half of the flask with distilled water. We shake the mixture and we add in more distilled water up to the level of $0.5L$. Find the molarity and molality.
$\mathbf{Attempt.... |
Which combinations of orbitals lead to pi bonds according to Valence Bond Theory? |
How would you balance this reaction:
$$\ce{Au(s) + NaCN(aq) + O2(g) + H2O(l)-> Na[Au(CN)2](aq) + NaOH (aq)}?$$
Here’s what I’m came up with. First we can balance any atoms besides hydrogen and oxygen in the reaction (like $\ce{Na}$ and $\ce{CN}):$
$$\ce{Au(s) + 2 NaCN(aq) + O2(g) + H2O(l) -> NaAu(CN)2 + NaOH ... |
How would you balance this reaction:
$$\ce{Au(s) + NaCN(aq) + O2(g) + H2O(l)-> Na[Au(CN)2](aq) + NaOH(aq)}?$$
Here’s what I’m came up with. First we can balance any atoms besides hydrogen and oxygen in the reaction (like $\ce{Na}$ and $\ce{CN}):$
$$\ce{Au(s) + 2 NaCN(aq) + O2(g) + H2O(l) -> Na[Au(CN)2](aq) + N... |
> Find the molality of a mixture formed by mixing $200cm^3$ of $HNO_3$ that has a $69\%$ of richness and density $1.41g/mL$, with $1L$ of the same acid with $1.2M$ and density $1.06g/mL$.
**Attempt.** The question asked the molarity too, and I think I've found it, but the issue comes with the molality. Pretty stuck ... |
> Find the molality of a mixture formed by mixing $200cm^3$ of $HNO_3$ that has a $69\%$ of richness and density $1.41g/mL$, with $1L$ of the same acid with $1.2M$ and density $1.06g/mL$.
**Attempt.** The question asked the molarity too, and I think I've found it, but the issue comes with the molality. Pretty stuck ... |
I'm wondering specifically about magnetite micro particles functionalized/silanated with (3-aminopropyl)triethoxysaline (APTES), though I assume the stability would be the same for most surfaces.
By stability, I mean can the APTES "fall off" the surface over time or in extreme conditions (pH, temperature, pressure, ... |
How stable are surfaces functionalized with APTES? |
I learned Fermi's Golden Rule applied to absorption and stimulated emission and encountered the following question:
Since absorption and emission rates are the same for stimulated emission, why can't we say that the incident beam is not attenuated by the sample? |
How to think about absorption and emission rates and intensity for stimulated emission? |
I have a very common air purifier: HEPA filter with a heavy duty helping of activated carbon and zeolite. My particular filter is designed for 5 years of operation under typical home conditions. In reality, I expect a few years, if not 5. I found this to be the case in the past.
I put an air purifier in the bedroo... |
Activated carbon + zeolite: Does relative humidity affect retention of VOCs? |
I have a very common air purifier: HEPA filter with a heavy duty helping of activated carbon and zeolite. My particular filter is designed for 5 years of operation under typical home conditions. In reality, I expect a few years, if not 5. I found this to be the case in the past.
I put an air purifier in the bedroo... |
My friend and I were debating about if Molarity is constant in a disolution if this one changes volume due to evaporation.
There was this problem that stated that 125 [mL] of sodyum chloride 0.122 [M] evaporates over time and final volume becomes 113 [mL]
I say Molarity keeps being constant, he says no because vo... |
Is Molarity constant? |
My take is that the terms "inorganic benzene" and "inorganic graphite" are meant to relay thoughts of both structural and chemical likeness to organic counterparts; however, graphite is not an organic compound since it is not a compound. It is an allotrope of carbon, just like diamond, buckminsterfullerene and graphene... |
Is there any indicator or a way of measuring purity of nitrogen? The lab-way of doing things is out of my reach and I was thinking about a DIY way. I want to decrease oxidising atmosphere in a container by introducing N3 but I am not sure about the purity of it.
Thank you |
Is there any indicator or a way of measuring purity of nitrogen? The lab-way of doing things is out of my reach and I was thinking about a DIY way. I want to decrease oxidising atmosphere in a container by introducing $\ce{N2}$ but I am not sure about the purity of it.
Thank you |
Is there any indicator or a way of measuring purity of nitrogen? The lab-way of doing things is out of my reach and I was thinking about a DIY way. I want to decrease oxidising atmosphere in a container by introducing $\ce{N2}$ but I am not sure about the purity of it. |
How to measure purity of nitrogen gas in a "homemade" way? |
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 have a very common air purifier: HEPA filter with a heavy duty helping of activated carbon and zeolite. My particular filter is designed for 5 years of operation under typical home conditions. In reality, I expect a few years, if not 5. I found this to be the case in the past.
I put an air purifier in the bedroo... |
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