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How does de Broglie actually proves Bohr's postulates? |
How does de Broglie actually prove Bohr's postulates? |
> The burning enthalpy (exothermic) of $\ce{NO +O2 ->NO2}$ is $\pu{57 kJ}$ and $\ce{O=O}$ bond energy is $\ce{494 kJ}$, then what is the bond energy of $\ce{N-O}$ ?
So I balanced the equation
$$\ce{2NO + O2 ->2NO2}$$
wrote down Lewis structures and got
$$(2[\ce{N=O}] + [\ce{O=O}]) - 2([\ce{N-O}] + [\ce{N=O}... |
> The burning enthalpy (exothermic) of $\ce{NO +O2 ->NO2}$ is $\pu{57 kJ mol^-1}$ and $\ce{O=O}$ bond energy is $\ce{494 kJ mol^{-1}}$, then what is the bond energy of $\ce{N-O}$ ?
So I balanced the equation
$$\ce{2NO + O2 ->2NO2}$$
wrote down Lewis structures and got
$$(2\Delta H(\ce{N=O}) + \Delta H(\ce{O... |
Why is it necessary to correct the pressure of a gas that is collected over water? |
Basically, what are some mistakes that you can make while using the downward displacement of water method and how to fix them? This is actually a homework question and I'm not too sure what it means either. |
Basically, what are some mistakes that you can make while using the downward displacement of water method and how to fix them? This is actually a homework question and I'm not too sure what it means either. The original question:
> State and explain Dalton’s Law of Partial Pressures. Why is it necessary to correct t... |
> The burning enthalpy (exothermic) of $\ce{NO +O2 ->NO2}$ is $\pu{57 kJ mol^-1}$ and $\ce{O=O}$ bond energy is $\ce{494 kJ mol^{-1}}$, then what is the bond energy of $\ce{N-O}$ ?
So I balanced the equation
$$\ce{2NO + O2 ->2NO2}$$
wrote down Lewis structures and got
$$(2\Delta H(\ce{N=O}) + \Delta H(\ce{O... |
Q : If 1 mole of gaseous carbon atoms are converted into diamonds , calculate enthalpy change of process given that Bond enthalpy of C-C bond is 400KJ/mole,
according to me , the answer should be that since C(diamond) has 4 bonds and C(gas) doesn't have any bonds , 4 bonds are being formed so enthalpy change shou... |
In [this][1] video, at 3:30 min professor solves two equations H2O —> H+ + OH- & HCl —> H+ + Cl- and says therefore...[H+] = [Cl-]+[OH-]. How come this happen from those two equations?
Can anyone elaborate and explain?
[1]: https://www.youtube.com/watch?time_continue=1&v=XY-mCaATdIY |
When you do these calculations be sure to keep track of your units and the actual reactions you are considering.
Burning methane is not the same as burning the same amount of carbon plus twice the amount of dihydrogen. You need to check the [specific heats of combustion][1] and you need to make sure you keep track ... |
Maximum bond energy is in F2, N2 or O2? |
For a quick general answer, this equation represents the charge balance. In a solution, the charges of all ions should add up to zero. You charge balance reads:
$$\ce{[H+] = [Cl-] + [OH-]}$$
If you had divalent ions, you would have to correct for that, e.g. if the solution also contained magnesium ions:
$$\ce{... |
As implied near the end of [this article][1], carbon nanotubes are usually synthesized in chunks on the order of about a centimeter in length. Why aren't we making them longer? Does it seem feasible to do so in the next 5 years, 10 years, 20 years?
[1]: https://arstechnica.com/science/2018/05/forget-carbon-fiber... |
Why is it hard to synthesize carbon nanotubes longer than a centimeter or so? |
As implied near the end of [this article][1], carbon nanotube fibers have been synthesized in chunks on the order of about a centimeter in length (Fei Wei at Tsinghua University in 2018). What is the cost per unit length for making these fibers? Does it seem feasible to do so in the next 5 years, 10 years, 20 years?
... |
What is the approximate cost per unit length to synthesis carbon nanotubes free of defects? |
When mixing HCl with K2CO3, the reaction that is usually given is the following:
K2CO3 + 2HCl → 2KCl + CO2 + H2O
I am wondering, however, if I could produce KHCO3 from K2CO3, by using half as many moles HCl. The reaction I imagine could happen would be expressed as follows:
K2CO3 + HCl → KHCO3 + KCl
I've g... |
What is the approximate cost per unit length to synthesize carbon nanotubes free of defects? |
In [this][1] video, at 3:30 min professor solves two equations
$$\ce{H2O —> H+ + OH-}$$
and
$$ \ce{HCl —> H+ + Cl-}$$
and deduces $[\ce{H+}] = [\ce{Cl-}] +[\ce{OH-}]$. How come this happen from those two equations?
Can anyone elaborate and explain?
[1]: https://www.youtube.com/watch?time_continue=1&v... |
> If 1 mole of gaseous carbon atoms are converted into diamonds, calculate enthalpy change of process given that bond enthalpy of $\ce{C-C}$ bond is $\pu{400 kJ mol-1}.$
According to me, the answer should be that since C(diamond) has 4 bonds and C(gas) doesn't have any bonds, 4 bonds are being formed so enthalpy cha... |
Is there free software which can calculate the fluorescence emission spectra of organic molecules?
Let's say for example: rubrene
There is a bunch of quantum free quantum chemistry software:
https://en.wikipedia.org/wiki/List_of_quantum_chemistry_and_solid-state_physics_software
However, which one would be the m... |
For the Elsevier's Reaxys data base, there is a [support page][1] you may consult without subscription, nor log-in to the product. Actually, this is more like a searchable directory, too, because you search for keywords, like «rank», too.
Doing so [here][2] -- time stamped 25/04/2019 -- offers insight about «How do... |
The problem I'm working on is:
At 1100 K and a total pressure of 1 atm, SO3 is 75.0% dissociated. 2SO3(g) -->(EQUILIBRIUM)<-- 2SO2(g)+ O2(g). Assume 1.00 mol of SO3 was present before dissociation.
Calculate the molarities of SO3, SO2, and O2 at equilbrium.
I've already found the moles at equilibrium to be 0... |
How would I find the molarity/concentration of a gas using PV = nRT? |
The problem I'm working on is:
> At 1100 K and a total pressure of 1 atm, $\ce{SO3}$ is 75.0% dissociated.
> $$\ce{2SO3(g) <=> 2SO2(g) + O2(g)}$$
> Assume 1.00 mol of $\ce{SO3}$ was present before dissociation.
> Calculate the molarities of $\ce{SO3},$ $\ce{SO2},$ and $\ce{O2}$ at equilibrium.
I've alr... |
The problem I'm working on is:
> At 1100 K and a total pressure of 1 atm, $\ce{SO3}$ is 75.0% dissociated.
> $$\ce{2SO3(g) <=> 2SO2(g) + O2(g)}$$
> Assume 1.00 mol of $\ce{SO3}$ was present before dissociation.
> Calculate the molarities of $\ce{SO3},$ $\ce{SO2},$ and $\ce{O2}$ at equilibrium.
I've alr... |
I am searching for experimental spin-orbit coupling constants, particularly for main group elements and Cr(0) to calculate correlation consistent Composite Approach (ccCA) energetics. This method requires the application of experimental spin-orbit coupling constants (Table 1; [ccCA paper][1]). I have found and read sev... |
Where to find experimental spin-orbit coupling constants? |
How would I find the molarity/concentration of a gas using pV = nRT? |
My reasoning for the somewhat implausible "$sp^2$" character of the hydrogen between these two oxygens on the enol structure of the right comes from recognizing that if it were, then we would have 6 $sp^2$ atoms with 6 $\pi$-electrons, so maybe that extra bit of instability from having a higher orbital on hydrogen coul... |
My reasoning for the somewhat implausible "$\mathrm{sp^2}$" character of the hydrogen between these two oxygens on the enol structure of the right comes from recognizing that if it were, then we would have 6 $\mathrm{sp^2}$ atoms with 6 π-electrons, so maybe that extra bit of instability from having a higher orbital on... |
Does alcohol hydrogen in the enol tautomer of a β-dicarbonyl have sp² character? |
I'm trying to quickly learn basic crystallographic principles **in 2D** under pressure (it's me whose under pressure, not the lattice) so I'm checking many sources to find those that "speak to me" the best (including [this excellent answer](https://chemistry.stackexchange.com/a/47868/16035). Many sources (books, papers... |
I'm trying to quickly learn basic crystallographic principles **in 2D** under pressure (it's me whose under pressure, not the lattice) so I'm checking many sources to find those that "speak to me" the best (including [this excellent answer](https://chemistry.stackexchange.com/a/47868/16035)). Many sources (books, paper... |
I'm trying to quickly learn basic crystallographic principles **in 2D** under pressure (it's me whose under pressure, not the lattice) so I'm checking many sources to find those that "speak to me" the best (including [this excellent answer](https://chemistry.stackexchange.com/a/47868/16035)). Many sources (books, paper... |
I'm trying to quickly learn basic crystallographic principles **in 2D** under pressure (it's me whose under pressure, not the lattice) so I'm checking many sources to find those that "speak to me" the best (including [this excellent answer](https://chemistry.stackexchange.com/a/47868/16035)). Many sources (books, paper... |
**How do I determine if a Metal Fluoride is soluble in liquid Gallium and under what conditions the Metal Fluoride will stay in solution in the liquid Gallium?**
I am involved in a project that is testing approaches to using CVD to form a graphene layer on liquid Gallium. Fluorine has been used in the process to dis... |
We all know that the alkali metals give *solvated electrons* in liquid ammonia which is responsible for the blue color of the solution.
It is stated, "the blue color of the solution is due to the ammoniated electron *which absorbs energy* in visible region of light."
But i couldn't understand why solvated elect... |
H Cl H H
| | | |
H - Cl - C = C - C - C - H
| | | |
H Cl H H
Can someone break down the steps for naming this?
Is it along the lines of, 4-ethyl-1,5-dimethyl-2-chloropentene? |
H Cl H H
| | | |
H - Cl - C = C - C - C - H
| | | |
H Cl H H
Can someone break down the steps for naming this?
Is it along the lines of 4-ethyl-1,5-dimethyl-2-chloropentene? |
H Cl H H
H C - C = C - C - C - H
H Cl H H
CH3 CCL = CCl CH2 CH3
Can someone break down the steps for naming this?
Is it along the lines of, 4-ethyl-1,5-dimethyl-2-chloropentene? |
H Cl H H
H C - C = C - C - C - H
H Cl H H
$$\ce{CH3-C(Cl)=C(Cl)-CH2-CH3}$$
Can someone break down the steps for naming this?
Is it along the lines of 4-ethyl-1,5-dimethyl-2-chloropentene? |
H Cl H H
H C - C = C - C - C - H
H Cl H H
CH3−C(Cl)=C(Cl)−CH2−CH3
Can someone break down the steps for naming this?
Is it along the lines of, 4-ethyl-1,5-dimethyl-2-chloropentene?
the initial diagram didn't turn out as i hoped it would. It's sup... |
CH3−C(Cl)=C(Cl)−CH2−CH3
Can someone break down the steps for naming this?
Is it along the lines of, 4-ethyl-1,5-dimethyl-2-chloropentene?
the initial diagram didn't turn out as i hoped it would. It's supposed to be 5 carbons. The first carbon has 3 hydrogens attached. The second has one chlorine att... |
Can someone break down the steps for naming $\ce{CH3-C(Cl)=C(Cl)-CH2-CH3}$?
Is it along the lines of 4-ethyl-1,5-dimethyl-2-chloropentene?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/h7ek4.png |
In my text book, it is written that NH3 is base. They mentioned the reason for this which is, it produces OH- ion in water. They stated this reaction,
> NH3 + H2O --> NH4OH
So That's why, they said that it is base.
But in neutralization reaction, stated by our teacher,
Acid + Base = Salt + water
So, if ... |
Is Ammonia (NH3) base? |
I want to calculate minimum detectable activity (MDA) at 662 keV energy of a gamma spectrometry by HPGe detector.
Assume 2 scenarios:
1. There is no peak at 662 keV. So net peak area is zero. Gross peak area is x unit.
2. There is a peak. Let's say net peak area is y unit. And gross peak area is z unit.
... |
I know this configuration violates the AufBau principal but does it also violate Hund's rule of maximum multiplicity? |
Does this electronic configuration violate the Hund's rule of maximum multiplicity? |
[EDITED]
If humans disappeared today, and aliens visited in the future, for how long would plastic or other "obviously" non-natural polymers be detectable on the planet, using known or plausible technology. That is, how likely would it be that the aliens would say: "Clearly, the presence of these molecules indicates... |
I'm trying to quickly learn basic crystallographic principles **in 2D** under pressure (it's me whose under pressure, not the lattice) so I'm checking many sources to find those that "speak to me" the best (including [this excellent answer](https://chemistry.stackexchange.com/a/47868/16035)). Many sources (books, paper... |
The image in [this question](https://chemistry.stackexchange.com/q/73755/16035) turned out to probably be wrong, but it still makes me wonder. Are there examples of crystals where the atoms within a unit cell can have *two (or more) different configurations or orientations* who's energies are so close that a sample cry... |
Are there examples of crystals with random mixtures of two unit cell configurations? |
The image in [this question](https://chemistry.stackexchange.com/q/73755/16035) turned out to probably be wrong, but it still makes me wonder. Are there examples of crystals where the atoms within a unit cell can have *two (or more) different configurations or orientations* who's energies are so close that a sample cry... |
Are there examples of crystals with random but static mixtures of two unit cell configurations? |
I have got a bioreactor with an aqueous medium which produces biomass (yeast; *S.cerevisiae*) after inoculation.
<br> I am observing and collecting data over the whole process via probes/etc. on different process parameters such as pH, temperature, offgas of $\ce{O_2}$ and $\ce{CO_2}$, base uptake ($\ce{NaOH}$), weigh... |
How can I determine the electrode potential of ethanoic acid redox reaction? |
I'm trying to quickly learn basic crystallographic principles **in 2D** under pressure (it's me whose under pressure, not the lattice) so I'm checking many sources to find those that "speak to me" the best (including [this excellent answer](https://chemistry.stackexchange.com/a/47868/16035)). Many sources (books, paper... |
I want to synthesize a new polyimide based on new diamine. In the first step of the synthesis of this diamine, my monomer was added to a mixture of 1-chloro-4-nitrobenzene and potassium carbonate in dimethylacetamide (used as the solvent) and stirred the mixture in $\pu{100 ^{\circ}C}$ for $\pu{24 h}$. The reaction mix... |
I'm trying to quickly learn basic crystallographic principles **in 2D** under pressure (it's me whose under pressure, not the lattice) so I'm checking many sources to find those that "speak to me" the best (including [this excellent answer](https://chemistry.stackexchange.com/a/47868/16035)). Many sources (books, paper... |
Soaps and detergent are both molecules that have a polar head and a long organic tail. In Soaps, the head is often a carboxylate ion $\ce{COO-}$ where as a detergent has a benzosulphonate $\ce{C6H11SO3-}$(or other) head:
[![enter image description here][1]][1]
I have often seen that detergents are 'stronger' tha... |
Why is detergent better at cleaning than soap? |
Is it correct to say that "Increasing the temperature will always increase the rate of any chemical reaction"?
Many articles on the internet and textbooks say yes but what about biochemical reactions that take place in our body?
To my knowledge at higher temperatures some enzymes (which are catalysts in chemical react... |
Why does the SCF not converge in a structure optimization with GAMESS of the thiourea molecule at the PM6 level of theory? |
I was coding a simple RHF code to test my understanding of computational chemistry when I stumbled upon this question. How exactly do computer programs like Gaussian, GAMESS-US etc. know which irreducible representation to assign to the molecular orbitals generated?
Thanks! |
How do computational chemistry programs determine the irreducible representation of a molecule? |
> How can I calculate the enthalpy for those balanced reaction given the data of $\ce{NO +O2 -> NO2}$ enthalpy?
The way the enthalpy data is presented is sloppy (is this the original text of the exercise?). For some types of enthalpy, it is unnecessary to specify the chemical reaction equation because there is a con... |
> How can I calculate the enthalpy for those balanced reaction given the data of $\ce{NO +O2 -> NO2}$ enthalpy?
The way the enthalpy data is presented is sloppy (is this the original text of the exercise?). For some types of enthalpy, it is unnecessary to specify the chemical reaction equation because there is a con... |
I would like to synthesis gold/polyacrilic acid (PAA) Janus nanoparticles in solution.
Any ideas how I can fictionalize gold with a photosensitizer and PAA with an antibody so that there would be no other unwanted interactions? |
Does aminosugars give positive response to [test for alkaloids][1] such as tests with Dragendorff's reagent, mayer's reagent, Hager's reagent, Wagner's reagent etc?
[1]: http://thepharmacistpharma.blogspot.com/2009/03/how-to-distinguish-alkaloids.html |
Does aminosugars give positive response in alkaloid tests? |
Possibly retracted soon, because I'm not aware how to include a picture in a comment to clarity your question. Do you mean instances like the following, where sites *seemingly* are occupied by two atoms simultanously -- as in analogues of Prussian blue -- just because the model deposit in the .cif is the average of th... |
**TL;DR:** PM6 only works for elements up to fluoride in GAMESS.
I have played around with the GAMESS version installed at our cluster, the ancient `5 DEC 2014 (R1)` and I came to the conclusion that there must be a *'bug'* in the implementation of PM6 with GAMESS. (I reproduced the problem with `20 APR 2017 (R1)`; ... |
I would like to synthesis gold/polyacrylic acid (PAA) Janus nanoparticles in solution.
Any ideas how I can functionalize gold with a photosensitizer and PAA with an antibody so that there would be no other unwanted interactions? |
I was coding a simple RHF code to test my understanding of computational chemistry when I stumbled upon this question. How exactly do computer programs like Gaussian, GAMESS-US etc. know which irreducible representation to assign to the molecular orbitals generated?
|
How do computational chemistry programs determine the irreducible representation of a molecular orbital? |
Possibly retracted soon, because I'm not aware how to include a picture in a comment to clarity your question. Do you mean instances like the following, where sites *seemingly* are occupied by two atoms simultanously -- as in analogues of Prussian blue -- just because the model deposit in the .cif is the average of th... |
I am searching for experimental spin-orbit coupling constants, particularly for main group elements and Cr(0) to calculate correlation consistent Composite Approach (ccCA) energetics. This method requires the application of experimental spin-orbit coupling constants (Table 1, \[1\]). I have found and read several other... |
Suppose that I have $\pu{100 mL}$ solution of strong acid, $\ce{HA}$, at $\pu{0.10 mol L^{-1}}$.
This solution is titrated with a strong base solution, $\ce{BOH}$, at $\pu{0.10 mol L^{-1}}$.
Suppose yet that a poorly/sparingly soluble salt, $\ce{BA}$ $(K_\ce{sp}=\pu{2.30×10^{-3}})$, is formed during titration.
The... |
How a titration curve is affected when a poorly soluble salt is formed? |
> The ionization energy of $\ce{He+}$ is $19.6 \times 10^{-18}~\mathrm{J~atom^{-1}}$. What is the energy of the first stationary state ($n=1$) of $\ce{Li^{2+}}$?
Since the question specifically states that $n=1$, I used the formula
\begin{align}
E &= -2.178 \times 10^{-18} \cdot \frac{Z^2}{n^2}.\\
E &= -2.178 ... |
Why does the first lithium stationary state have n = 9/4? |
Why is the hydroxide ion not considered to be amphoteric.
Why is $$\ce{2OH- <<=> H2O + O^{2-} }$$ not considered ??
Even though the equilibrium would mostly lie towards the left but still the hydroxide ion can accept a hydrogen ion and donate hydrogen ion , but still it fits the definition for an **Amphoteric substan... |
I have a plasma consisting of elements A and B (which have a similar mass). These elements can react to form molecules AB.
$$
\ce{A + B -> AB}
$$
Now if my plasma or gas is expanding based on pressure gradients, I will have some sort of diffusion of these two element concentrations. Based on my spectroscopic an... |
If I have a solution of salt or sugar dissolved in water, the solute will never settle out or "fall to the bottom", no matter low long I wait. Why is that?
Since salt and sugar (in their pure, solid forms) are denser than water, I would intuitively expect that gravity would eventually pull all the salt and sugar to ... |
Why doesn't the solute settle out of a solution, such as brine, sugar water, or air? |
> How a titration curve is affected when a poorly soluble salt is formed?
If by "I think that titration curve don't be affected" you mean that the graph of pH vs volume of strong base will not be affected by the precipitations, then you are right. This is because the species that form the precipitate are not part of... |
Here's the boring answer: Toothpaste is a mixture of some solids and some liquids.
The question "is it solid or liquid?" makes sense when you're talking about a substance or a mixture with a single [phase](https://en.wikipedia.org/wiki/Phase_(matter))—that is, a substance or mixture that's pretty much completely uni... |
The following website ([link][1]) mentions a Ksp of 6.3 x 10-10 for CuBr2 but I suspect this might be incorrect.
Could anyone confirm or refute that Ksp value?
[1]: https://www.chegg.com/homework-help/questions-and-answers/2-calculate-molar-solubility-cubr2-ksp-63-x-10-10--water-b-010m-cu-cn-2-solutio... |
Ksp of CuBr2 in water? |
I want to make a series of standards to make a calibration curve. The analyte is a volatile substance so I'll have to use some glass "containers" with a membrane lit so I don't lose too much of the analyte. The glass container has a certain volume so when making my stock solution the amount of solvent I will use is fix... |
I've been thinking how refrigerants - which are highly potent greenhouse gases (hundreds and even thousands of times more potent than CO2) - are likely to be vented to atmosphere eventually either due to system leakage, accident, neglect, theft of chiller units, or deliberate discharge. It makes me wonder if, for clima... |
Can common refrigerants be chemically converted into something that is a stable solid at STP? |
[One of the questions from chegg.com][1] mentions $K_\mathrm{sp}(\ce{CuBr2}) = 6.3\cdot 10^{-10}$, but I suspect this value might be incorrect.
Could anyone confirm or refute that $K_\mathrm{sp}$ value?
[1]: https://www.chegg.com/homework-help/questions-and-answers/2-calculate-molar-solubility-cubr2-ksp-63-x-... |
How about heating a metal hydroxide such as [magnesium hydroxide](https://en.wikipedia.org/wiki/Magnesium_hydroxide)? At sufficiently high temperature the hydroxide decomposes according to the reaction
$\ce{Mg(OH)2 -> MgO + H2O}$
which is most simply interpreted as a proton transfer from one hydroxide ion to ano... |
An elder way would be the *via* book examples, like «Organic Structures from Spectra» by Field, Sternhell, Kalman, with dozens and dozens of combined exercises in a format like the following:
[![enter image description here][1]][1]
and currently available in the 5th edition by Wiley (e.g., [here][2]). There is a ... |
When 4-methylcycloprop-1-ene reacts with bromine, then 1,2-dibromo-4-methylcyclopropane forms. And I am stuck on determining the amount of stereoisomers that can form as a result.
For the bromine positions we have:
- trans-(1R,2R)
- trans-(1S,2S)
- cis-(1R,2S)
- cis(1S,2R)
But there is a werid t... |
An elder way would be the *via* book examples, like «Organic Structures from Spectra» by Field, Sternhell, Kalman, with dozens and dozens of combined exercises in a format like the following:
[![enter image description here][1]][1]
and currently available in the 5th edition by Wiley (e.g., [here][2]). There is a ... |
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