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I measured the UV-absorption-spectrum of benzene vapor as well as solved in methanol and cyclohexane. The absorption of the vapor was much stronger than in solution, my guess would be that this is due to the better distribution in air, correct? I also noticed that the peaks are slightly shifted to longer wavelengths - ... |
Can someone explain how does this ring expansion occur with the mechanism? I do understand that the hydride shift occurred because of carbocation stability but why did the ring expand? Can you please attach a mechanism if possible?
[![][1]][1]
[![.][2]][2]
[1]: https://i.stack.imgur.com/IIEZh.png
[2]... |
Thickness of proton exchange membrane (Nafion)? |
Why and how does ring expansion occur in the dehydration of (cyclobut-3-ene-1,2-diyl)dimethanol? |
I believe it is cost. According to [1], food-grade stainless steel works well as a container for milk.
However, the article also says that the wholesale cost of a 0.568 L (19.2 fluid ounce) glass milk bottle in Great Britain was 0.35 £ ($0.50) in 2020.
By contrast, I searched a few wholesale sites, and the lea... |
I know that the incomplete combustion of a hydrocarbon produces CO or sometimes C if the amount of oxygen is very limited, but I was wondering if at first CO2 is produced and only when there isn't enough O, then CO and C are produced? Or is only CO and C produced from the beginning of the reaction? My question if the a... |
The *cyaphide* anion $\ce{(CP)-}$ should be chemically similar to its nitrogen analogue cyanide. $\ce{(CN-})$ But unlike it's counterpart it readily polymerizes so it has only been found in outer space naturally. However, it should form compounds that should be the same like cyanides.For example sodium cyanide ($\ce{... |
The *cyaphide* anion $\ce{(CP)-}$ should be chemically similar to its nitrogen analogue cyanide. $\ce{(CN-})$ But unlike it's counterpart it readily polymerizes so it has only been found in outer space naturally. However, it should form compounds that should be the same like cyanides.For example sodium cyanide ($\ce{... |
The multiplicity is fundamentally defined as $2S + 1$ where $S$ is the total spin.
From what I understand, the multiplicity corresponds with the number of unpaired/paired electrons. For example, in the case of $\ce{Cu^2+}$:
[![Cu2+ electronic configuration][1]][1]
The single unpaired electron in $\ce{Cu^2+}$ m... |
I know that the incomplete combustion of a hydrocarbon produces $\ce{CO}$ or sometimes $\ce{C}$ if the amount of oxygen is very limited, but I was wondering if at first $\ce{CO2}$ is produced and only when there isn't enough oxygen, then $\ce{CO}$ and C are produced? Or is only $\ce{CO}$ and $\ce{C}$ produced from the ... |
I know that the incomplete combustion of a hydrocarbon produces $\ce{CO}$ or sometimes $\ce{C}$ if the amount of oxygen is very limited, but I was wondering if at first $\ce{CO2}$ is produced and only when there isn't enough oxygen, then $\ce{CO}$ and C are produced? Or is only $\ce{CO}$ and $\ce{C}$ produced from the ... |
Does incomplete combustion produce carbon dioxide at first? |
I know that Raoult's law holds true only for a non volatile solute in a volatile solvent mixture wherein the vapour pressure of the solution gets lowered due to the addition of solute.
1) Now, first of all does it hold for a mixture of immiscible liquids ?
2) Does it hold for a mixture of immiscible liquids under... |
>There is a range of elimination reactions with E1cb at one end, E1 at the other end and E2 in between. It is not uncommon for these different reaction pathways to compete with one another. For example, in some elimination reactions, the E1 and E2 pathways can operate in competition with one another. Activation energy ... |
A want to ask this question again:
https://physics.stackexchange.com/questions/7284/thermodynamics-of-evaporation#:~:text=Thermodynamics%20of%20evaporation-,thermodynamics,given%20temperature%20inside%20the%20container.
Specifically this part:
"Now imagine the experiment is repeated but instead of vacuum conditi... |
Will addition of inert gas change the vapour pressure of a liquid? |
In 2,6-chlorobenzoic acid the -COOH group is pushed out of the plane restricting resonance.
# My question: #
Does it mean the -I effect of chlorine atoms also cannot operate and reduce the charge on the deprotonated acid?
 |
Does SIR(Steric hindrance in resonance) affect inductive effect? |
In 2,6-dichlorobenzoic acid, the $\ce{-COOH}$ group is pushed out of the plane restricting resonance.
[![enter image description here][1]][1]
**Question**: Does it mean the -I effect of chlorine atoms also cannot operate and reduce the charge on the deprotonated acid?
[1]: https://i.stack.imgur.com/SpPJ4.... |
> Why are they carcinogenic?
From my point of view as a medicinal chemist, polycyclic aromatic hydrocarbons compounds tend to be metabolized by specific cytochrome P450 (CYP 450) isoforms to form highly electrophilic species, which are highly reactive and can react with the DNA of the cell and damage it. Specificall... |
From this question on Physics SE [Thermodynamics of evaporation](https://physics.stackexchange.com/questions/7284/):
> Now imagine the experiment is repeated but instead of vacuum conditions, the water is pressurized with nitrogen at 1 atm. According to the phase diagram of water, liquid is the stable form of water ... |
Why is there a methyl shift in this reaction. I believe that the +R effect by 2 phenyl groups would be better than the +R effect by oxygen because of its lone pair. Can somebody please confirm?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/UcloK.png |
Why is there a methyl shift in this reaction? |
LCAO states that orbitals only combine if the energies and shape of the orbitals are same. 2 p orbitals of Cl and 1 s orbitals of H are the ones forming the bond by sharing electrons but how? |
All definitions in the IUPAC Gold Book refer to *standard* values:
> **exergonic reaction (exoergic reaction)** [[link](https://goldbook.iupac.org/terms/view/E02262)]
>
> This expression is often applied to a reaction for which the overall
> *standard* Gibbs energy change ΔG° is negative. Some workers use this
... |
LCAO states that orbitals only combine if the energies and shape of the orbitals are same. 3 p orbitals of Cl and 1 s orbitals of H are the ones forming the bond by sharing electrons but how? |
Why is there a phenyl shift in this reaction. I believe that the +R effect by 2 phenyl groups would be better than the +R effect by oxygen because of its lone pair. Can somebody please confirm?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/UcloK.png |
Why is there a phenyl shift in this reaction? |
Linear combination of atomic orbitals (LCAO) states that orbitals can only combine if the energies and shape of the orbitals are same. $3p$ orbital of Chlorine and $1s$ orbital of Hydrogen are the ones forming the bond by sharing electrons but how? |
How can orbitals of Hydrogen and Chlorine atom combine to form molecular orbitals of Hydrogen Chloride? |
From Atkins' Physical Chemistry,
>The electronegativity is a parameter introduced by Linus Pauling as a measure of the
power of an atom to attract electrons to itself when it is part of a compound. Pauling used valence-bond arguments to suggest that an appropriate numerical scale of electronegativities could be de... |
I have to prove scientifically why a sodium ascorbate solution in water turns yellowish - reddish over time. I know ascorbic acid is supposed to oxidize into dehydroascorbic acid, and the latter then oxidizes into more subproducts... But I have to prove this by using UV-vis spectroscopy and whenever I analyze the yello... |
I measured the UV-absorption-spectrum of benzene vapor as well as solved in methanol and cyclohexane. The absorption of the vapor was much stronger than in solution, my guess would be that this is due to the better distribution in air, correct? I also noticed that the peaks are slightly shifted to longer wavelengths - ... |
I have to prove scientifically why a sodium ascorbate solution in water turns yellowish - reddish over time. I know ascorbic acid is supposed to oxidize into dehydroascorbic acid, and the latter then oxidizes into more subproducts... But I have to prove this by using UV-vis spectroscopy and whenever I analyze the yello... |
I have to prove scientifically why a sodium ascorbate solution in water turns yellowish - reddish over time. I know ascorbic acid is supposed to oxidize into dehydroascorbic acid, and the latter then oxidizes into more subproducts... But I have to prove this by using UV-vis spectroscopy and whenever I analyze the yello... |
In order to calculate the equilibrium constant we must know the value of $Δ_rG^{\circ}$ (which is a function of $T$) so we can calculate $K$ as:
$$K=e^\frac{{-Δ_rG^{\circ}}}{RT}$$
Now if the standard state is changed (for example from $1$ atm to $3$ atm) would the equilibrium constant change? My intuition says no... |
Why is standard state useful? |
Helium and neon are the two most unreactive elements in the Periodic Table, but could they form compounds with an element such as fluorine that won't spontaneously explode and decompose outside of the lab? Radon, xenon, krypton, and even argon already do form fluorides(well argon forms argon fluorohydride). It said in... |
In order to calculate the equilibrium constant we must know the value of $Δ_rG^{\circ}$ (which is a function of $T$) so we can calculate $K$ as:
$$K=e^\frac{{-Δ_rG^{\circ}}}{RT}$$
Now if the standard state is changed (for example from $1$ atm to $3$ atm) would the equilibrium constant change? My intuition says no... |
In order to calculate the equilibrium constant we must know the value of $Δ_rG^{\circ}$ (which is a function of $T$) so we can calculate $K$ as:
$$K=e^\frac{{-Δ_rG^{\circ}}}{RT}$$
Now if the standard state is changed (for example from $1$ atm to $3$ atm) would the equilibrium constant change? My intuition says no... |
In order to calculate the equilibrium constant we must know the value of $\Delta_\mathrm{r}G^{\circ}$ (which is a function of $T$) so we can calculate $K$ as:
$$K = \exp\left(-\frac{\Delta_\mathrm{r}G^{\circ}}{RT}\right)$$
Now if the standard state is changed (for example from $\pu{1 atm}$ to $\pu{3 atm}$) would ... |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/s8LWW.png
Hey all,
I'm a little confused as to why we ignore the effect the lone pair has on the geometry of the molecule when it is participating in resonance. Wouldn't it be the case that the molecule is actually in some hybrid state ... |
How to understand geometry of lone pair in resonance? |
> Wouldn't it be the case that the molecule is actually in some hybrid state of trigonal planar and trigonal pyramidal?
"Hybrid state" refers to the distribution of **electrons**, not nuclei. Different resonance structures can have different electron distributions, but they can't have nuclei in different places, whi... |
I noticed that the reaction of ozone with $\ce{I_2}$ gives iodic acid and not periodic acid. Upon searching, I found this question:
https://chemistry.stackexchange.com/questions/69811/why-does-iodine-get-oxidized-to-iodic-acid-and-not-periodic-acid-by-nitric-acid/69813#comment311863_69813
The answer says, nitric ... |
Can ozone oxidise iodine to periodic acid? |
On the image [![image][1]][1], can someone help me how to draw the different butyl cations? I'm confused as to where to place the positive charge on the different butyl cations. Going from left to right, the compounds are: isobutyl cation, n-butyl cation, and sec-butyl cation. Thank you so much!
[1]: https://i.s... |
How to draw the different butyl cations? |
So, I am working on a series of octahedral complexes of the type $\ce{[M(CO)2(CH3)X3]-}$ where $\ce{M} = \ce{Co}, \ce{Rh}, \ce{Ir}$ and $\ce{X}$ is a range of ligands (halides, cyanide, nitrosyl etc.). Now, the complexes all have either a mirror plane or a $C_2$ axis which makes the **two $\ce{CO}$ ligands equivalent b... |
The alkali metals have increasing densities as we go down the group. I thought the alkali metals gradually get denser down the group .Lithium has a density of 535 kg/m3,sodium with 970 kg/m3 **potassium with 862 kg/m3** ,rubidium with 1,530kg/m3 and cesium with 1,900kg/m3.But until potassium alkali metals got denser an... |
Why is potassium less dense than sodium? |
Why are f-f transitions spin forbidden? |
Fehling's test follows a single electron transfer mechanism, with electron transfer form the substrate to $Cu^{2+}$, which forms $Cu^{1+}$finally giving reddish brown precipitate of $Cu_2O$. The mechanism is as follows:
[![enter image description here][1]][1]
Now it can be easily concluded from the above mechanis... |
Does formaldehyde and ethylene glycol give positive fehling's test? |
What would be the major product of 4-chloro-1 pentanol reacting with water? Would cyclization occur? Would this be a type of substitution or elimination reaction?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/XxNp5.png
|
I was taught in high school that carbon atoms by themselves are capable of establishing covalent bonds with with as far as four hydrogens atoms.
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/pydrH.png
Nowadays, trying to understand the topic in-depth, I am confused about orbitals r... |
What happens to the 2s orbital in carbon-hydrogen bonds? |
Fehling's test follows a single electron transfer mechanism, with electron transfer form the substrate to $\ce{Cu^2+}$, which forms $\ce{Cu^1+}$finally giving reddish brown precipitate of $\ce{Cu2O}$. The mechanism is as follows:
[![Fehling's test mechanism][1]][1]
Now it can be easily concluded from the above ... |
Does formaldehyde and ethylene glycol give positive Fehling's test? |
Consider:
[![Enter image description here][1]][1]
I'm a little confused as to why we ignore the effect the lone pair has on the geometry of the molecule when it is participating in resonance. Wouldn't it be the case that the molecule is actually in some hybrid state of trigonal planar and trigonal pyramidal?
B... |
How should I understand the geometry of a lone pair in resonance? |
A problem was given in which the order of rate of decarboxylation was asked for the compounds cyclopropane carboxylic acid and and butanoic acid. It's known that the rate here depends on the stability of carbanion intermediate formed during the reaction. The answer was given that the rate of cyclopropane carboxylic aci... |
I learnt that with the increase of concentration, conductance of tr electrolyte decreases. While looking for the reason I found in my textbook that if concentration increase, amount of ions increases too. And for that ion-ion interaction gets a bit increased and lowers the speed of individual ions. Opposite thing occu... |
So, I am working on a series of octahedral complexes of the type $\ce{[M(CO)2(CH3)X3]-}$ where $\ce{M} = \ce{Co}, \ce{Rh}, \ce{Ir}$ and $\ce{X}$ is a range of ligands (halides, cyanide, nitrosyl etc.). Now, the complexes all have either a mirror plane or a $C_2$ axis which makes the **two $\ce{CO}$ ligands equivalent b... |
So, I am working on a series of octahedral complexes of the type $\ce{[M(CO)2(CH3)X3]-}$ where $\ce{M} = \ce{Co}, \ce{Rh}, \ce{Ir}$ and $\ce{X}$ is a range of ligands (halides, cyanide, nitrosyl etc.). Now, the complexes all have either a mirror plane or a $C_2$ axis which makes the **two $\ce{CO}$ ligands equivalent b... |
Potassium has a density of 0.86g/cm3 and sodium has a density of 0.97g/cm3,even though potassium is below sodium and the alkali metals should have increasing densities down the group.WHy is this the case? And all of the answers I found were either nothing related to the thing I was talking about at all or were very vag... |
Potassium has a density of $\pu{0.86g/cm3}$ and sodium has a density of $\pu{0.97g/cm3}$,even though potassium is below sodium and one might expect the alkali metals to exhibit monotonously increasing densities down the group. Why is this discrepancy the case? All of the answers I found were either unrelated or vague. |
Which has the best yield for CaSO4? |
We have the following equilibrium established in a container with movable piston at atmospheric pressure.
$$\ce{N_2 (g) + 3 H2 (g) ⇌ 2NH_3 (g)}$$
Now how does the **concentration** of the reacting species change upon addition of $\ce{He(g)}$ to the container?
I know that the reaction would shift towards left becau... |
Although density may be a relatively easily measurable property of solid materials, it may not suggest the most fundamental relationship between mass and volume for the elements. Molar volume (the volume required to contain 6 x 10$^{23}$ atoms of each the elements) is pictured in the graph below (WebElements):
[ and all of that. The... |
Multicentre bonds like these (in this case, a 3-centre-2-electron or '3c2e' bond) are pretty fascinating and there is a lot of theoretical work that goes on to understand these. I am a chemist as well, and [had to go through learning Wade's rules](https://chemistry.stackexchange.com/a/110451/16683) and all of that. The... |
In my understanding every operation we do in $\log_{10}$ can be done in the natural logarithm itself, and it should be better because mathematical integrals naturally give out expressions involving the natural logarithm function.
However, it seems that in my chemistry books, at least the one's I've used, there wa... |
Why do chemists like to work in log base 10? |
In my understanding, every operation we do in $\log_{10}$ can be done in the natural logarithm itself and it should be better because mathematical integrals naturally give out expressions involving the natural logarithm function.
However, it seems that in my chemistry books, there are elaborate schemes set up to avo... |
In my understanding, every operation we do in $\log_{10}$ can be done in the natural logarithm itself and it should be better because mathematical integrals naturally give out expressions involving the natural logarithm function.
However, it seems that in my chemistry books there are elaborate schemes set up to avoi... |
Why do chemists like to work with common logarithms (base 10)? |
I came across this question as part of my homework, and the answer I got was 1,1,1,2,3,3,3-heptachloro-2-(trichloromethyl)propane. But when I look up the question online, most sources say the answer 2-(trichloromethyl)-1,1,1,2,3,3,3-heptachloropropane, even though chloro comes before trichloromethyl alphabetically. Wha... |
*All* fields of science (biology, chemistry, physics, and geology) use *both* natural and base-10 logarithms.
Is there a distinguishing characteristic that (typically) determines when one is used vs. the other? Yes: *There is a class of applications where the natural log is used, and a qualtitatively different clas... |
*All* fields of science (biology, chemistry, physics, and geology) use *both* natural and base-10 logarithms.
Is there a distinguishing characteristic that (typically) determines when one is used vs. the other? Yes: *There is a class of applications where the natural log is used, and a qualtitatively different clas... |
*All* fields of science (biology, chemistry, physics, and geology) use *both* natural and base-10 logarithms.
Is there a distinguishing characteristic that (typically) determines when one is used vs. the other? Yes: *There is a class of applications where the natural log is used, and a qualtitatively different clas... |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/v2rrT.png
For the Tosylate ion, the negatively charged oxygen is stabilized via resonance with the oxygen atoms. But what are the orbitals of sulfur that are involved in the overlap? Is the sulfur sp2 hybridized and thus have a p-orbital f... |
*All* fields of science (biology, chemistry, physics, and geology) use *both* natural and base-10 logarithms.
Is there a distinguishing characteristic that (typically) determines when one is used vs. the other? Yes: *There is a class of applications where the natural log is used, and a qualtitatively different clas... |
> What is the IUPAC name of $\ce{(CCl3)3CCl}?$
The answer I got was **1,1,1,2,3,3,3-heptachloro-2-(trichloromethyl)propane**. But when I looked up the question online, most sources say the answer is **2-(trichloromethyl)-1,1,1,2,3,3,3-heptachloropropane**, even though ‘chloro’ comes before ‘trichloromethyl’ alphabet... |
What is the IUPAC name of perchloroisobutane? |
*All* fields of science (biology, chemistry, physics, and geology) use *both* natural and base-10 logarithms.
Is there a distinguishing characteristic that (typically) determines when one is used vs. the other? Yes: *There is a class of applications where the natural log is used, and a qualtitatively different clas... |
[![enter image description here][1]][1]
For the Tosylate ion, the negatively charged oxygen is stabilized via resonance with the oxygen atoms. But what are the orbitals of sulfur that are involved in the overlap? Is the sulfur $\ce{sp^2}$ hybridized and thus have a p-orbital for resonance?
If it is $\ce{sp^2}$, ... |
*All* fields of science (biology, chemistry, physics, and geology) use *both* natural and base-10 logarithms.
Is there a distinguishing characteristic that (typically) determines when one is used vs. the other? Yes: *There is a class of applications where the natural log is used, and a qualtitatively different clas... |
Why do chemists work with common logarithms (base 10)? |
While going through my book, I came across the following observation:
>$\Delta H_{eg1}$ is positive for Be and Mg
Where $\Delta H_{eg1}$ is the first electron gain enthalpy.
It seemed quite reasonable as Be and Mg have fully filled $\ce{ns^2}$ configuration and also that the incoming electron would en... |
Why is Electron Gain Enthalpy of only Be and Mg positive, in group 2? |
my name‘s Tristan and I‘m a bachelor‘s student in Germany. I‘m trying to synthesize an injectable nanocomposite hydrogel for wound closure and wound healing applications. The problem is that, next to bioactive glass nanoparticles, I‘d like to incorporate chitosan or carboxymethyl chitosan (https://doi.org/10.1016/j.ijb... |
>What is the *n*-factor of $\ce{Fe2S3}$ in this reaction?
>
> $$\ce{Fe2S3 + O2 -> FeSO4 + SO2}$$
I broke this reaction down into two parts
$$\ce{Fe2S3 -> FeSO4}$$
$$\ce{Fe2S3 -> 3 SO2}$$
And in the second case the change in electrons is 18. But how do we find it in the first reaction?
I think this is a... |
What is the n-factor of ferric sulfide when it reacts with oxygen to give ferrous sulfate and sulfur dioxide? |
There are 14 types of Bravais lattices one of them is hexagonal which is just present as primitive cell ie the basis are at its corners , now when I read about hexagonal closed packing I came to know that it is a part of hexagonal system (from here [![enter image description here][1]][1]
) But it confused me that if i... |
Another statement of second law of thermodynamics can be formulated in terms of system properties and not properties + surroundings (isolated system). For a closed system at constant temperature and pressure:
$$dG_{T,p,n_i} \leq 0$$
**Are $n_i$ constant during a process?**
We know that during a chemical reaction... |
Do the differential expressions of second law of thermodynamics imply a smooth increase in entropy? |
We have made confounding observations in the physiology lab working with inorganic phosphate. The cell processes we study rely upon the transport of diprotonated inorganic phosphate. But we get different results whether the extracellular buffers are bicarbonate or HEPES. We wonder if the two buffering systems, bicarbon... |
>Do the two buffering systems, bicarbonate vs HEPES, differ in their making available diprotonated vs monoprotonated inorganic phosphate at $\mathrm{pH \ 7.4}$, room temperature?
I do not have any physiology lab experience. However, my general knowledge is telling me that you have not completely disclosed what physi... |
How can I free base cystamine dihydrochloride? (SOLVED) |
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