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[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/SqJLt.jpg
In the above diagram, 1 and 2 wouldn't be on the same plane, right? If the double bond connected to 2 was between it and 1, they would be, but is it correct that now they're both planar but on different planes? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/SqJLt.jpg
In the above diagram, 1 and 2 wouldn't be on the same plane as that of the ring, right? If the double bond connected to 2 was between it and 1, they would be, but is it correct that now they're both planar but on different planes... |
I often see U or even $\Delta$U being the symbol for lattice energy. Why is that? Does it refer to internal energy?
Thanks |
Why is U the symbol for lattice energy? |
I often see $U$ or even $\Delta U$ being the symbol for lattice energy. Why is that? Does it refer to internal energy? |
There are only two resonance structures of allyl anion with negative charge distributed over positions 1 and 3:
$$\ce{\overset{-}{C}H2-CH=CH2 <-> CH_2=CH-\overset{-}{C}H2}.$$
What's the criteria for electrons forming a double bond? Why isn't there a third resonance structure
$$\ce{\overset{+}{C}H2-\overset{-}{... |
> PhOH(toluene) ⇌ PhOH (aq).
> An aqueous solution contain $1.5*10^{-2}$M phenol and is shaken with the same volume of toluene. Determine the equilibrium concentration of PhOH(toluene). $K_D = 14$
I have done lots of similar questions and each time I think I've gotten the method of how to do these types of questio... |
How will you carry out the following conversion? i.e. cyclization of 2-(2-methtlbutyl) nitro cyclohexane..(please check the image enclosed) |
I'm actually quite surprised that this isn't really mentioned anywhere on the internet (or I'm just bad at searching)! Solubility in water is known to be directly related by multiple factors, and for organic molecules it's usually ability to form hydrogen bonds, polarity, bulk etc. I would imagine this trend would cont... |
What determines solubility (or miscibility) in organic solvents? |
I'd like first to answer your question:
>My question is, when writing the formula for $K_\mathrm{D}$, is the organic phase always in the numerator and the aqueous phase in the denominator?
The answer is yes. The IUPAC Recommendations 1993 (Ref.1) defines Partition Ratio ($K_\mathrm{D}$) as follows (also see [the ... |
>The equation for equilibrium of solvent-solvent extraction is:
$$\ce{PhOH(toluene) <=> PhOH (aq)}$$
> An aqueous solution contain $\pu{1.5 \times 10^{-2} M}$ phenol and is shaken with the same volume of toluene. Determine the equilibrium concentration of $\ce{PhOH(toluene)}$. $K_\mathrm{D} = 14$
I have done lots... |
I've so far handled only concentrated fuming Nitric, Sulfuric & hydrochloric acids from the inorganic side. Even during an accidental spill on the hand I did say only the HNO3 affects the skin by turning it yellow and the top layer sometimes peels off.
But in the organic acid side I've had once experience in the pa... |
Does 99.8% acetic acid cause sever skin burns like formic acid? |
After studying displacement at school, I wondered if it is possible to reduce the toxic gas of carbon monoxide to less harmful and more useful substances, like so:
Carbon monoxide + metal -> Carbon + metal oxide
Where the metal is of course more reactive than carbon, higher in the reactivity series, and so would ... |
Could Carbon Monoxide be reduced by oxidising a more reactive metal? |
According to Molecular Orbital theory, (O2)2+ has a greater bond order than O2 and 2 less antibonding electrons. So why is molecular oxygen O2 more stable than the molecular ion (O2)2+?
one possible reason that comes to mind is that the Antibonding orbitals, although higher in energy than the constituent atomic orbi... |
Why is O2 more stable than (O2)2+? |
According to Molecular Orbital theory, (O2)2+ has a greater bond order than O2 and 2 less antibonding electrons. So why is molecular oxygen O2 more stable than the molecular ion (O2)2+?
one possible reason that comes to mind is that the Antibonding orbitals, although higher in energy than the constituent atomic orbi... |
I've so far handled only concentrated fuming nitric, sulfuric & hydrochloric acids from the inorganic side. Even during an accidental spill on the hand I did say only the $\ce{HNO3}$ affects the skin by turning it yellow and the top layer sometimes peels off.
But in the organic acid side I've had once experience in... |
Does 99.8% acetic acid cause severe skin burns like formic acid? |
What would be more precise to find the volume of a cube of metal and why?
1: Measuring cube with a ruler and calculating volume
2: Calculating the water displacement of the cube with a graduated cylinder
(1-2 Sentences) |
[[how the cyclization can take place as there is no other functional group than NO2....i have put hard efforts but cannot make out to the product. It would be of immense help if anyone can answer....The one way that I can think off is photochemical bromination which occur slectively at tertiary centre which then can be... |
This question is based on [@Heisenberg's Question](https://chemistry.stackexchange.com/questions/9679/why-does-having-equivalent-resonance-structures-give-more-stability) with the same title.
I recently offered a bounty for a more detailed answer for the same question.
These are the things I would like to be in the... |
According to Molecular Orbital theory, $\ce{(O2)^{2+}}$ has a greater bond order than $\ce{O2}$ and 2 less antibonding electrons. So why is molecular oxygen $\ce{O2}$ more stable than the molecular ion $\ce{(O2)^{2+}}$?
One possible reason that comes to mind is that the Antibonding orbitals, although higher in energ... |
Why is $\ce{O2}$ more stable than $\ce{(O2)^{2+}}$? |
>How will you carry out the following conversion? i.e. cyclization of $2$-($2$-methylbutyl) nitro cyclohexane.
How the cyclization can take place as there is no other functional group than $\ce{NO_2}$ , I have put hard efforts but cannot make out to the product. It would be of immense help if anyone can answer. The ... |
How will you carry out the following conversion? i.e. cyclization of 2-(2-methylbutyl) nitro cyclohexane |
How the cyclization can take place as there is no other functional group than $\ce{NO2}$ , I have put hard efforts but cannot make out to the product. It would be of immense help if anyone can answer. The one way that I can think of is photochemical bromination which occur selectively at tertiary center which then can ... |
How will you carry out cyclization of 2-(2-methylbutyl) nitro cyclohexane? |
So between the change of phases within the matter(solid liquid gas), the temperature reaches a plateau, no matter how much heat you add to it, it just stays the same. Where did all those energy go? |
In a heating curve, when it is plateau, where does all the energy go since the temperature does not get higher? |
The Hofmann-Loeffler-Freytag reaction as suggested by @user55119 in the comments above is the way to go.
First you need to reduce your nitro group. The reduction of alkyl nitro compounds is less simple than aromatic nitro groups and lower yielding in general. I would suggest the use of Al/Hg amalgam.
Acetylate th... |
According to molecular orbital theory (MOT), $\ce{O2^2+}$ has a greater bond order than $\ce{O2}$ and two less antibonding electrons. So why is molecular oxygen $\ce{O2}$ more stable than the molecular ion $\ce{O2^2+}?$
One possible reason that comes to mind is that the antibonding (AB) orbitals, although higher in ... |
Why is oxygen more stable than oxygen dication? |
Should I number substituent or double bond? |
How the cyclization can take place as there is no other functional group than $\ce{NO2}?$
[![1‐(2‐methylbutyl)‐2‐nitrocyclohexane to 2‐ethyl‐2‐methyl‐octahydroindole][1]][1]
One way that I can think of is photochemical bromination which occurs selectively at tertiary center which then can be promoted to give cati... |
How to carry out cyclization of 1‐(2‐methylbutyl)‐2‐nitrocyclohexane? |
I'm studying equilibria and thermodynamics and came across these two terms.
My problem is, unlike other thermodynamic properties that I can understand physically like volume, pressure, enthalpy etc. *do these two quantities have physical significance* or, is it just that we define fugacity (without any physical mean... |
I am a high school student and I am a little confused in the techniques used to purify organic compounds, for e.g we study in steam distillation we reduce the external pressure on the compound to be purify by passing steam over it, which reduces its boiling point
1)first of all, how is that possible? In first look I... |
The Hofmann-Loeffler-Freytag reaction as suggested by @user55119 in the comments above is the way to go.
First you need to reduce your nitro group. The reduction of alkyl nitro compounds is less simple than aromatic nitro groups and lower yielding in general. I would suggest the use of Al/Hg amalgam.
Acetylate th... |
You have to consider the system as a whole - you can't directly compare $\ce{O_2}$ and $\ce{O_2^2+}$ because they have different numbers of particles. To put it another way when you consider the relative stability of two interconvertible specifies you really have to write down a chemical reaction that connects them, ... |
You have to consider the system as a whole - you can't directly compare $\ce{O_2}$ and $\ce{O_2^2+}$ because they have different numbers of particles. To put it another way when you consider the relative stability of two interconvertible specifies you really have to write down a chemical reaction that connects them, ... |
I am doing a school project to extract anthocyanin from a fruit. I chose blueberry. What is a step by step method to extract the anthocyanin? I have to do it in school so hopefully its not a very complex procedure. Also, im not allowed to use methonal as it is flammable. From what i have researched, i should use ethano... |
How do I extract anthocyanin from a blueberry? |
> Liquid methanol is obtained with carbon monoxide gas and hydrogen gas in a reactor at $\pu{300 °C}$ and $\pu{250 atm}.$ $K_p = \pu{9.28E-3}.$ Find $K_c.$
With only these data, do I have to use the following equilibrium for the calculations
$$\ce{CO(g) + 2 H2(g) <=> CH3OH(l)},$$
or do I have to suppose first... |
A past paper question on solid state NMR I was looking at asks why, in $^{13}$C CP MAS NMR, carbons directly bonded to nitrogen are "occasionally" split, and why they're usually absent in the dipolar dephased spectra.
I assume this is probably due to quadrupolar interactions, since $^{14}$N has spin 1; the size of t... |
Why are 13C CP MAS NMR signals sometimes split by N, and absent in dipolar dephasing? |
I recently learned that osmosis occurs when there is a semipermeable membrane between pure water and a solution of water. The pure water then fills up the solution's side until, as my textbook put it,
>"The pressure exerted by this column of solution counterbalances the pressure exerted by the water moving through ... |
How does hydraulic equilibrium work on the particulate level? |
I recently learned that osmosis occurs when there is a semipermeable membrane between pure water and a solution of water. The pure water then fills up the solution's side until, as my textbook put it,
>"The pressure exerted by this column of solution counterbalances the pressure exerted by the water moving through ... |
What is a possible conventional interpretation of Wilfred Hagen's puzzling Electron Paramagnetic Resonance spectrum? |
The membrane has plenty of holes that are a little bit bigger than small molecules like water. Bigger molecules or bigger ions like usual solutes cannot go through these holes. So water has the tendency to cross the membrane both ways. When a water molecule hits a hole in the membrane from the pure water side, it can c... |
This question is based on [@Heisenberg's Question](https://chemistry.stackexchange.com/questions/9679/why-does-having-equivalent-resonance-structures-give-more-stability) with the same title.
I recently offered a bounty for a more detailed answer for the same question.
These are the things I would like to be in the... |
I understand why KCl has a higher specific conductivity than NaCl.. but I dont understand why the curvature is more significant for NaCl (KCl is a straight line). Ive provided a picture of this here, and this is also what I get from my experiment. Does anyone mind explaining why?[![enter image description here][1]][1]
... |
Why does the specific conductivity against concentration curve for NaCl curve more than KCl? |
What spectrum of light does penetrate fog? |
The dish-washing detergent, which you can find an image of [here][1], has the following hazard symbol on its back:
[![Hazard symbol for corrosive][2]][2]
On the back, it additionally says that if it comes in contact with the skin, you should immediately wash with lots of water, however the detergent also says "sp... |
How can a detergent "designed for sensitive skin" warrant the "corrosive" hazard symbol? |
The dish-washing detergent, which you can find an image of [here][1], has the following hazard symbol on its back:
[![Hazard symbol for corrosive][2]][2]
On the back, it additionally says that if it comes in contact with the skin, you should immediately wash with lots of water, however the detergent also says "sp... |
We know that molecules have different energy states (vibrational, rotational, electronic). Using Boltzmann distribution we can find the popoulation of each energy state. If we have only electronic states (e.g. atoms) then we can find the population of the ground, first excited state etc. If we have a molecule (neglecti... |
Does population of vibrational states depend on population of electronic states? |
We learn about indicators but these seem awfully useless if you have no clue what pH the color change occurs at. How did early chemists figure this out? I guess more broadly, how was the hydronium content even measured in the first place? |
Historical question: How was pH measured back in the day if you had nothing to calibrate to? |
Calculate EAN for [Fe(diars)2Cl2]Cl? |
The term thermodynamic stability is used on this site, but I can't find a good definition. Is is a quantitative or a qualitative concept? Does it apply to a single compound, or a pair of compounds? Does it a relative or an absolute value?
An [answer][1] to another question, https://chemistry.stackexchange.com/quest... |
What is the definition of thermodynamic stability? |
How was pH measured back in the day if you had nothing to calibrate to? |
I am trying to remove heavy rust from a carbon steel 10-inch carving knife. Mothers Polish did not get rid of much of the rust. I turned to vinegar soaking and scrubbing: At first it took off a good bit of the rust leaving visible residue in the bottom of a glass carafe. With a lot rust left I turned to vinegar and sal... |
Bond polarity, as far as I understand, is a measure of the degree * direction to which shared electron density is distorted, and thus solely depends on the electronegativity difference.
Up until now, I had learnt that the dipole moment (charge on each atom x separation) is used as a measure of the polarity. However... |
Does formal charge affect bond polarity? |
When we do nitrosation of phenols, we get para-nitrosophenol as the major product, which tautomerises to quinone mono oxime. [This article](https://pubs.acs.org/doi/10.1021/ja01318a062) states that it largely exists in the quinonoid form.
My question is, why? I know that nitroso form is less stable than the oxime f... |
The boiling points of four para-derivatives of phenol are:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/oCpd6.png
How can we compare the boiling points of *p*-nitrophenol and *p*-aminophenol?
Apart from the hydroxyl group, *p*-nitrophenol has two oxygen atoms to form inter-mole... |
How would we know if we have never experimentally seen them? |
How do we know orbitals of atoms and elements exist? |
I am currently building a reaction mechanism through Gaussian calculations. I successfully found each TS and intermediates through the different jobs (opt, freq, irc) for my 3-step mechanism from reactants to my products.
However, I was questioning myself about one step in particular which could involve one extra mo... |
Reaction pathway - Extra molecule used in one step only? |
While qualitatively comparing the acidic nature of o-methyl benzoic acid and benzoic acid, we consider the steric effect due to which the -COOH group loses its planarity and the +M effect of -CH3 isn't considered any longer. But still, the +I of CH3 is functioning, which increases the electron density of the compound a... |
I have a theory which may be wrong but I will write it down.If 2 elements at the same group (in solids)have the same crystal structure then the one with the biggest interatomic spacing has better electric conductivity.I don't know if anyone else has found this but I will give you 2 examples:
The crystal structure of... |
The modern definition of thermodynamic stability is the state of maximum entropy. Some background information is necessary to make sense of this. I hope you will find the following helpful!
Phenomenologically, thermodynamic stability is the absence of visible change. This is the 'original' definition, employed b... |
The modern definition of thermodynamic stability is the state of maximum entropy. Some background information is necessary to make sense of this. I hope you will find the following helpful!
Phenomenologically, thermodynamic stability is the absence of visible change. This is the 'original' definition, employed b... |
The modern definition of thermodynamic stability is the state of maximum entropy.
Some background information is necessary to make sense of this. I hope you will find the following helpful!
Phenomenologically, thermodynamic stability is the absence of visible change. This is the 'original' definition, employ... |
I am looking at how metal ions (Fe2+, Ni2+, Cu2+, Zn2+, and Ag+) affect the biochemical oxygen demand in water and used the wrinkler's method to find out the oxygen concentration of each solution. I graphed this with oxygen concentration (y axis) and increasing atomic number (x axis) and found that the order: Fe2+, Ni... |
why does dissolved oxygen concentration decrease with increasing atomic number (metals)? (desperate need of help) |
I am looking at the [code][1] of [DeepHF][2] that computes $\Delta G_{\text{binding}}$, and I see that it breaks a sequence into overlapping 2-mers and compute a weighted sum according to a dictionary with 16 key values:
def dG_binding(seq):
seq = seq.lower()
dG = {'aa': -0.2, 'tt': -1, 'at': -... |
Is there a terse but rigorous introduction to MOT? I'm looking for the 'Berge's Real Analysis' of MOT, if that analogy resonates with anyone. If not, I'm looking for a book that I can use as a reference rather than a gentle tutorial. |
I am looking at how metal ions (Fe2+, Ni2+, Cu2+, Zn2+, and Ag+) affect the biochemical oxygen demand in water and used the Winkler's method to find out the oxygen concentration of each solution. I graphed this with oxygen concentration (y axis) and increasing atomic number (x axis) and found that the order: Fe2+, Ni2... |
Why does dissolved oxygen concentration decrease with increasing atomic number of metals? |
As you see, I still post...
I studied chemisty decades ago (and when I was through with all the compulsory practica, I was sent to a computer chemistry workgroup and politely suggested to never touch a beaker again, which I happily followed and made my PhD there, otherwise probably the chemistry dept. of the univers... |
Is there a specific historical figure or era that is most responsible for our current definitions of "physical change" and "chemical change"? |
For the reaction: P4(s)+5O2(g) ---> P4O10(s)
Let's say SOME P4O10(s) is removed from the reaction. Will that effect equilibrium?My assumption is no, since P4O10(s) is not included in the equilibrium expression.
However, for me, it gets confusing when let's say P4O10(s) is COMPLETELY removed. In this case, I would... |
Does partially/completely removing solid shift the equilibrium? |
From the [Toxic Substance Portal of ATSDR][1], "The [almond] odor of hydrogen cyanide is detectable at 2-10 ppm (OSHA PEL = 10 ppm), but does not provide adequate warning of hazardous concentrations. Perception of the odor is a genetic trait (20% to 40% of the general population cannot detect hydrogen cyanide)." Howeve... |
For the reaction: $$\ce{P4(s) + 5O2(g) -> P4O10(s)}$$
Let's say SOME $\ce{P4O10(s)}$ is removed from the reaction. Will that effect equilibrium? My assumption is no, since $\ce{P4O10(s)}$ is not included in the equilibrium expression.
However, for me, it gets confusing when let's say $\ce{P4O10(s)}$ is COMPLETELY... |
I am looking at how metal ions ($\ce{Fe^2+}$, $\ce{Ni^2+}$, $\ce{Cu^2+}$, $\ce{Zn^2+}$, and $\ce{Ag+}$) affect the biochemical oxygen demand in water and used the Winkler's method to find out the oxygen concentration of each solution. I graphed this with oxygen concentration ($y$ axis) and increasing atomic number ($x... |
From the [Toxic Substance Portal of ATSDR][1], "The [almond] odor of hydrogen cyanide is detectable at 2-10 ppm (OSHA PEL = 10 ppm), but does not provide adequate warning of hazardous concentrations. Perception of the odor is a genetic trait (20% to 40% of the general population cannot detect hydrogen cyanide)." Howeve... |
The formula for the work done by adiabatic expansion of gas is
$$W = C_V\,\mathrm dT.$$
Why the *volumetric* heat capacity $C_V$ is constant and not the heat capacity at constant pressure $C_p?$ If the system is at constant volume, it is a isovolumetric process and hence no work can be done in that case. |
I have been studying thermodynamics for quite a time now, and recently learned about enthalpy
but I have been facing a lot of problems
So,which is the correct equation of enthalpy
$$\Delta H=\Delta U+\Delta (PV)$$
or
$$\Delta H=\Delta U+P\De... |
I am having trouble conceptualizing endergonic reactions and their difference from endothermic reactions. An endergonic reaction is one that has a positive Gibbs free energy change, such that energy is taken in for the reaction to take place; in biological systems the very exergonic breakdown of ATP is a major source. ... |
Can endergonic reactions be driven by heat? |
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