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Why does Nitrogen Oxide NO exist? |
Why doesn't unstable odd electron compound $\ce{NO}$ dimerize to $\ce{N2O2}$? Why doesn't this structure of ozonide dimerize? But why then does $\ce{BH3}$ dimerizes to $\ce{B2H6}$, and $\ce{AlCl3}$ to $\ce{Al2Cl6}$, both with something like bridged bonds?
![enter image description here][1]
[1]: https://i.stac... |
Odd electron species do dimerize.
>$\ce{NO}$
Nitric oxide dimerizes, but only at [low temperature][1] (and probably high pressure}.
>$\ce{NO2}$
Nitrogen dioxide does dimerize. In fact, this is a [well known property][2] of $\ce{NO2}$. $\ce{NO2}$ (orange-brown) is in equilibrium with $\ce{N2O4}$ (colorless... |
Like you said, the 2 doublets at around $\pu{7 ppm}$ belong to a *para*-substituted benzene. The three single-proton multiplets around $\pu{5-6 ppm}$ belong probably to a single substituted alkene. A singlet and a doublet between $3$ and $\pu{4 ppm}$ belong to $\ce{CH3-{}}$ and $\ce{-CH2-{}}$ groups, respectively (Note... |
The change from the liquid state of water to the water vapor requires a large latent heat to loosen the hydrogen bonds. The process of transpiration in the plant involves exactly this change of state. Here, the water evaporates from the lower leaf surface and the leaf gives up some of its heat. In this way, the leaf is... |
I thought that d-orbitals were used to "extend the octet rule" in these molecules until I looked it up on Google and saw that they actually contributed only a little to the molecule. A little, but not zero.
My question is:
1. Is there a hypervalent period-3-element molecule that has mathematically been proved not to ... |
I thought that d-orbitals were used to "extend the octet rule" in these molecules until I looked it up on Google and saw that they actually contributed only a little to the molecule. A little, but not zero.
1. Is there a hypervalent period-3-element molecule that has mathematically been proved not to involve d-orb... |
Is there a hypervalent molecule which has no contribution of d-orbitals at all? |
Why melting and boiling are considered as equilibrium processes even though the amount (concentration) of both phases keep changing i.e from solid to liquid and so on. ? |
melting and boiling ...really equilibrium? |
What is the final product?
According to me, it's option (3). But given answer in the booklet is (2).
Given primary alcohol undergoes SN2 reaction to produce isopentyl bromide and the latter again undergoes SN2 to form isopentyl cyanide.... |
> [![Etymology of Formic Acid][1]][1]
[1]: https://i.stack.imgur.com/5qOT0.jpg
SRC: Google (Oxford)
So, we know that 'Formic Acid' was derived in formic acid in the late 18th century from the Latin word 'formica'.
> Formica is a genus of ants of the family Formicidae, commonly known as wood ants, mound ... |
Formic Acid vs Formica - Which came first? |
So I got myself a large Erlenmeyer flask, some steel wool and the bleach from the bathroom, mixing them under safe conditions in small quantities to see the sparky reaction I'd heard about. Trouble is, I didn't know the bleach we had was non-chlorine!
Disappointed, I left the mixture alone and uhm.. forgot about it.... |
Why are melting and boiling considered equilibrium processes even though the amount (concentration) of both phases keep changing i.e from solid to liquid and so on? |
> [![Etymology of Formic Acid][1]][1]
[1]: https://i.stack.imgur.com/5qOT0.jpg
>Source: Google(Oxford)
So, we know that 'Formic Acid' was derived in formic acid in the late 18th century from the Latin word 'formica'. From Wikipedia:
> Formica is a genus of ants of the family Formicidae, commonly known a... |
For the past few weeks, I have been studying Quantum Chemistry and lately in these lectures something has bugged me:
If I do a sum:
> $1 \times 2 \times 3 \times {...} $
This is the same as simply writing the order in reverse:
> $ {...} \times 2 \times 1 $
a bit like $ab = ba$
and for wave functions, ... |
Order of coordinates in a wavefunction - why do they matter? |
I am trying to use `OpenBabel` to compute Universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
for i in range(len(smiles)):
mol = molecules[i].OBMol
ff = ob.OBForceField.FindForceField('UFF')
ff.... |
is it possible to predict the density of water having just its molecular structure(basically obtain 1 g/cm^3 at 3.96°C)?
Are you aware of research/textbook that dive into this topic?
is it able to predict also the variation of the density with the temperature?
an equivalent question will be: how is it possible... |
>[OP] Why are melting and boiling considered equilibrium processes [...]
They should not be considered equilibrium processes. If melting is defined as the process where there is a net change from solid to liquid phase, this is not an equilibrium. If boiling is defined as the process where liquid turns into vapor (ro... |
I am trying to use `OpenBabel` to compute Universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
for i in range(len(smiles)):
mol = molecules[i].OBMol
ff = ob.OBForceField.FindForceField('UFF')
ff.... |
>[OP] Why are melting and boiling considered equilibrium processes [...]
They should not be considered equilibrium processes. If melting is defined as the process where there is a net change from solid to liquid phase, this is not an equilibrium. If boiling is defined as the process where liquid turns into vapor (ro... |
The lattice energy of a solid ionic compound is the energy released when one mole of the solid compound is formed from its constituent gaseous ions at $\ce {298 K}$ and $\ce {1 bar}$. However, gaseous ions (e.g. $\ce {K^+ (g), Cl^- (g)}$) do not exist at such temperatures. Thus, how is it possible that the lattice ener... |
I think what you are asking is this:
Consider a gas-phase chemical reaction, say A(g) + B(g) --> C(g). At equilibrium, the chemical potentials of all species are the same. Associated with this is an equilibrium constant,
$$K_p(T) = \frac{\frac{p_c}{p^o}}{\frac{p_A}{p^o}\frac{p_B}{p^o}},$$
which specifies... |
I think what you are asking is this:
Consider a gas-phase chemical reaction, say A(g) + B(g) --> C(g). At equilibrium, the chemical potentials of all species are the same. Associated with this is an equilibrium constant,
$$K_p(T) = \frac{\frac{p_c}{p^o}}{\frac{p_A}{p^o}\frac{p_B}{p^o}},$$
which specifies... |
Can 1,3-butadidyne show conjugation ?
As 1c and 3c are sp hybridized so there are two unhybridised p orbital mutually perpendicular to each other also these orbitals are separated by a sigma
There is possibility that it could show conjugation , im not able to confirm this hypothesis as i don't have reliable resources |
Ionization isomerism is defined as complexes which have same empirical formula but ionize to different ions in solution.
Consider the complex $\ce{[Pt(NH3)4Cl2]I2}$. The other possible ionization isomers are:
$\ce{[Pt(NH3)4I2]Cl2}$ and $\ce{[Pt(NH3)4ICl]ICl}$.
But I have not come across the complexes similar to ... |
Is it possible to predict the density of water having just its molecular structure (basically obtain 1 g/cm<sup>3</sup> at 3.96 °C)?
Are you aware of research/textbook that dive into this topic?
Is it able to predict also the variation of the density with the temperature?
An equivalent question will be: how is... |
I think what you are asking is this:
Consider a gas-phase chemical reaction, say
$$\ce{A(g) + B(g) <=> C(g)}.$$
At equilibrium, the chemical potentials of all species are the same. Associated with this is an equilibrium constant,
$$K_p(T) = \frac{\displaystyle\frac{p_\ce{C}}{p^\circ}}{\displaystyle\frac... |
A [separate question on this site][1] asked whether a one-component system is at equilibrium when melting or boiling, and the disparate answers where somewhat dependent on the definition of phase equilibrium. The term "phase equilibrium" seems to imply that under certain conditions, a one-component system with two phas... |
How is a phase equilibrium defined for one-component systems? |
A [question on this site][1] asked whether a one-component system is at equilibrium when melting or boiling, and the disparate answers where somewhat dependent on the definition of phase equilibrium. [Another question][2] asks whether two phases can ever exist in equilibrium at the boiling point. The term "phase equili... |
A [question on this site][1] asked whether a one-component system is at equilibrium when melting or boiling, and the disparate answers where somewhat dependent on the definition of phase equilibrium. [Another question][2] asks whether two phases can ever exist in equilibrium at the boiling point. The term "phase equili... |
How is a phase equilibrium defined for a one-component system? |
A [question on this site][1] asked whether a one-component system is at equilibrium when melting or boiling, and the disparate answers were somewhat dependent on the definition of phase equilibrium. [Another question][2] asks whether two phases can ever exist in equilibrium at the boiling point. The term "phase equilib... |
The conclusion is left to the reader. I believe that there is no useful value in involving d-orbitals in the description of "hypervalent" molecules while remaining on the level of the octet rule.
-------------------------
A typical example for when the octet rule seems to fail is sulfur hexafluoride.
**The nai... |
I think what you are asking is this: Equilibria for chemical reactions require specific ratios of products to reactants (as expressed by the equilibrium constant). *By contrast, equilibria for phase transitions don't require specific ratios of products to reactants.* [For instance, at the phase transition between i... |
I think what you are asking is this: Equilibria for chemical reactions require specific ratios of products to reactants (as expressed by the equilibrium constant). *By contrast, equilibria for phase transitions don't require specific ratios of products to reactants.* [For instance, at the phase transition between i... |
I think what you are asking is this: Equilibria for chemical reactions typically* (see note at end) require specific ratios of products to reactants (as expressed by the equilibrium constant). *By contrast, equilibria for phase transitions don't require specific ratios of products to reactants.* [For instance, at t... |
Does a neutral dimercury molecule ($\ce{Hg2}$) exist? Simple answer is yes. But when I look at the answers given so far, a simple answer might not be good enough without giving some evidence. So, I decided to dig into the question a little deeper. I'm not a physical chemist, but can't resist the data I have seen in rev... |
Deuterium-depleted water (DDW) is sold commercially by some companies. It is apparently manufactured by fractional distillation, which leverages differences in boiling points of heavy and light water.
My question is this: can DDW be manufactured through a freezing method? Heavy water has a freezing point of 38.8 °F... |
I am trying to use `OpenBabel` to compute Universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
for i in range(len(smiles)):
mol = molecules[i].OBMol
ff = ob.OBForceField.FindForceField('UFF')
ff.... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
for i in range(len(smiles)):
mol = molecules[i].OBMol
ff = ob.OBFo... |
I think what you are asking is this: Equilibria for chemical reactions typically* (see note at end) require specific ratios of products to reactants (as expressed by the equilibrium constant). *By contrast, equilibria for phase transitions don't require specific ratios of products to reactants.* [For instance, at t... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
I think what you are asking is this: Equilibria for chemical reactions typically* (see note at end) require specific ratios of products to reactants (as expressed by the equilibrium constant). *By contrast, equilibria for phase transitions don't require specific ratios of products to reactants.* [For instance, at t... |
The wavelengths for emissions in the visible region for Group 1 elements is as follows :
**Li** - 670.8 *nm*
**Na** - 589.2 *nm*
**K** - 766.5 *nm*
**Rb** - 780.0 *nm*
**Cs** - 455.5 *nm*
Now, considering that the ionisation enthalpies decrease going down the group, it should be relatively easier to remove an electro... |
The wavelengths for emissions in the visible region for Group 1 elements is as follows:
- $\ce{Li}:\pu{670.8 nm}$
- $\ce{Na}:\pu{589.2 nm}$
- $\ce{K}:\pu{766.5 nm}$
- $\ce{Rb}:\pu{780.0 nm}$
- $\ce{Cs}:\pu{455.5 nm}$
Now, considering that the ionisation enthalpies (I.E.s) decrease goi... |
The wavelengths for emissions in the visible region for Group 1 elements is as follows:
- Li - 670.8 nm
- Na - 589.2 nm
- K - 766.5 nm
- Rb - 780.0 nm
- Cs - 455.5 nm
Now, considering that the ionisation enthalpies (I.E.s) decrease going down the group, it should be relatively easier to remove... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
I am trying to use [Open Babel](http://openbabel.org/wiki/Main_Page) (OB) to compute universal force field (UFF) given an `xyz` file. I read each `xyz` file and turn it into a pybel molecule. Here is the code I have so far
def xyz_to_smiles(fname: str) -> str:
mol = next(pybel.readfile("xyz", fname))
... |
The wavelengths for emissions in the visible region for Group 1 elements is as follows:
$$
\begin{array}{lc}
\hline
\text{Element} & λ/\pu{nm} \\
\hline
\ce{Li} & 670.8 \\
\ce{Na} & 589.2 \\
\ce{K} & 766.5 \\
\ce{Rb} & 780.0 \\
\ce{Cs} & 455.5 \\
\hline
\end{array}
$$
Now, considering that the ionisat... |
Why does the emission wavelength of sodium appear to be an exception despite the trend for ionisation enthalpies among alkali metals? |
Can 1,3-butadidyne show conjugation in both the free p orbitals ?
As 2c and 3c are sp hybridized so there are two unhybridised p orbital mutually perpendicular to each other in each of carbon atom also these two orbitals are separated by a sigma bond.
There is possibility that it could show conjugation , im not able... |
How does maltose form its osazone crystal? If osazone is to be formed, then there must be aldehyde form for phenylhydrazine to react, but maltose is formed after hemiacetal formation. How do we address this? |
I have an assignment question for second year inorganic, which asks to rank the intensity of d-d transitions for a number of complexes. 2 are [Fe(OH2)6]3+ and [Fe(CN)6]4-. Both will have Laporte-forbidden transitions, but which will be 'more forbidden', so to speak? |
Which would have a more intense transition: a low spin d6 complex or a high spin d5 complex? |
I have an assignment question for second year inorganic which asks to rank the intensity of d-d transitions for a number of complexes. Two are $\ce{[Fe(OH2)6]^3+}$ and $\ce{[Fe(CN)6]^4-}.$ Both will have Laporte-forbidden transitions, but which will be 'more forbidden', so to speak? |
You see that both cases are Laporte-fotbidden, now how about _spin-forbidden_?
Assuming the complex vibrates so it's no longer exactly octahedral, can you make a spin-allowed transition for $\ce{Fe(CN)_6^{4-}}$? How about $\ce{Fe(H_2O)_6^{3+}}$? When you answer this you will answer your question. |
Is there a food-safe hydrophobic liquid with a substanially higher density than water? |
You see that both cases are Laporte-fotbidden, now how about _spin-forbidden_?
Assuming the complex vibrates so it's no longer exactly octahedral, can you make a spin-allowed transition for $\ce{Fe(CN)_6^{4-}}$? How about $\ce{Fe(H_2O)_6^{3+}}$? When you answer this you will answer your question.
>! You should ... |
Are there any known catalysts that can combine hydrogen and oxygen into water?
Does this type of reaction have a name? Trying to search for information, it seems to be all about splitting hydrogen and oxygen, is there any work on combining these and some catalysts that could be used? |
Can oxygen gas in air react with Mn3O4 to form MnO2? |
First of all, I know a similar question has already been asked & answered about σ values in general, however, I am not 100 % sure this answer is correct for the following situation.
So for the σ values, we know we have the following formula:
$$\log(\frac{K_x}{K_h})=\sigma_x$$
with the equilibrium values being... |
How are σ+ values in Hammett Plots calculated? |
First of all, I know a similar question has already been asked & answered about σ values in general, however, I am not 100 % sure this answer is correct for the following situation.
So for the σ values, we know we have the following formula:
$$\log \left(\frac{K_x}{K_h} \right)=\sigma_x$$
with the equilibrium... |
I came across a statement saying,
> "Consider a square planar coordination compound of type [MA2X2]. Then,
> if the compound is in a cis form, it shows optical activity as there
> is no plane of symmetry and hence is non-superimposable on its mirror
> image. On the other hand, a trans form is symmetric and superi... |
I think what you are asking is this: Equilibria for chemical reactions typically* (see note at end) require specific ratios of products to reactants (as expressed by the equilibrium constant). *By contrast, equilibria for phase transitions don't require specific ratios of products to reactants.* [For instance, at t... |
I think what you are asking is this: Equilibria for chemical reactions typically* (see note at end) require specific ratios of products to reactants (as expressed by the equilibrium constant). *By contrast, equilibria for phase transitions don't require specific ratios of products to reactants.* [For instance, at t... |
Peter Sykes mentions in the book *Guidebook to Mechanism in Organic Chemistry* (6th ed.) on p. 137 that:
> Highly reactive aromatic compounds, such as phenol, are found to undergo ready nitration even in dilute nitric acid, and at a far more rapid rate than can be explained on the basis of the concentration of $\ce{... |
Im confused about what type of reaction occurs between the (+)-bis salt of (+)-phenylsuccinic acid and HCl. Would this be considered an acid base reaction? Plz help asap! TY:) |
Im confused about what type of reaction occurs between the (+)-bis salt of (+)-phenylsuccinic acid and HCl. Would this be considered an acid base reaction or a neautralization reaction?
MY THOUGHTS: I know that an acid-base reaction occurs between (+)-phenysuccinic acid and (-)-proline to make the (bis)+ salt, im c... |
It is intuitive that the second ionisation will require more energy than the first. However, I'm having trouble explaining exactly why. I came across this other question on a similar topic: https://chemistry.stackexchange.com/questions/69633/why-second-ionisation-energy-greater-than-the-first/69636#69636
The answer ... |
It is intuitive that the second ionisation will require more energy than the first. However, I'm having trouble explaining exactly why. I came across this other question on a similar topic: https://chemistry.stackexchange.com/questions/69633/why-second-ionisation-energy-greater-than-the-first/69636#69636
The answer ... |
Consider the question :
The reaction of cyanamide, NH2CN (s), with dioxygen was carried
out in a bomb calorimeter, and ∆U was found to be –742.7 kJ mol–1
at 298 K. Calculate enthalpy change for the reaction at 298 K.
NH2CN(s) +3/2 O2 (g) → N2 (g) + CO2 (g) + H2O(l)
ΔH = ΔU + ΔnRT could be used to find ΔH.
I... |
> The reaction of cyanamide, $\ce{NH2CN(s)},$ with dioxygen was carried
out in a bomb calorimeter, and $∆U$ was found to be $\pu{–742.7 kJ mol-1}$
at $\pu{298 K}.$ Calculate enthalpy change for the reaction at $\pu{298 K}.$
$$\ce{NH2CN(s) + 3/2 O2(g) → N2(g) + CO2(g) + H2O(l)}$$
$ΔH$ could be found from
$$ΔH... |
I've just been getting into organic and been reading about H-H related to NMR. I've been seeing articles state how recasting of H-H is necessary and want to know how equations like below are derived.
> $$σ_\mathrm{peak} = σ_\ce{HA} + \frac{Δσ}{1 + 10^{(\mathrm{p}K_\mathrm{a} - \mathrm{pH})}}\tag{1}$$
> $$y = y_\m... |
Given these two molecules, I realize that the molecules are pretty identical in terms of the individual atoms' electronegativities (with Sulfur only being a small bit higher than Carbon). So then, the only factors that I can think of contributing to differences in dipole moment would be shape (tetrahedral vs trigonal p... |
Does H2SO or H2CO have a higher dipole moment? |
How do i know how much energy i need to obtain 20 g alumunium?
I calculated the quantity of electricity is 2.22 F.
Any help appreciated! |
I would like to know the role of Tautomerism, if any, in increasing stability of an Organic compound Moreover, how is it different from that of Hyperconjugation?
I know that Hyperconjugation involves shifting of protons between adjacent
atoms in different hypothetical structures to form a practical Hybrid structur... |
How do I know how much energy I need to obtain 20 g alumunium from alumina with 5 V?
I calculated the quantity of electricity is 2.22 F.
Any help appreciated! |
I would like to know the role of tautomerism, if any, in increasing stability of an organic compound. Moreover, how is it different from that of hyperconjugation?
I know that hyperconjugation involves shifting of protons between adjacent
atoms in different hypothetical structures to form a practical hybrid structu... |
The output data of mass spectrometers is relative intensity (y axis) over m/z (x axis). How is the distance between m/z values called? |
How is the distance between m/z values in mass spectrums called? |
The output data of mass spectrometers is relative intensity (y axis) over m/z (x axis). How is the distance between m/z values on the x-axis called (in case of centroided data and profile/raw data respectively)? |
How is the distance between m/z axis values in mass spectrums called? |
What is the difference between ideal stages and transfer units in a packed bed gas absorber? |
2HgO --> 2Hg + O2 delta H=+182 kJ
Correct answer is 20.5 kJ. I get 10.5 kJ. Here's how I did it:
1) Grams to moles: 200,59+16=216,59 g (using molar masses)
25g * (1 mole/216,59g) = 0,12 moles
2) Moles to kJ: 0,12 * (182kJ/2moles) = 10.5 kJ
What did I do wrong? |
How many kilojoules are needed to react 25.0 g of mercury1II2 oxide? |
How many kilojoules are needed to react 25.0 g of mercury(II) oxide? |
The following image is from [this answer](https://chemistry.stackexchange.com/a/15909/81509) for the question [Why is one lobe of an sp3 hybridized orbital smaller than its other half?](https://chemistry.stackexchange.com/q/15907/81509):
[![enter image description here][1]][1]
I understood everything from that an... |
What is the type of orbital depicted in this diagram? |
I've just been getting into organic and been reading about H-H related to $\mathrm{NMR}$. I've been seeing articles state how recasting of H-H is necessary and want to know how equations like below are derived.
> $$σ_\mathrm{peak} = σ_\ce{HA} + \frac{Δσ}{1 + 10^{(\mathrm{p}K_\mathrm{a} - \mathrm{pH})}}\tag{1}$$
>... |
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