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In crystalline solids, atoms might displace from their original position to create a vacancy in their original spot. This is referred to as Frenkel Defect. Why does this defect increase the dielectric constant of the solid? |
Why does the dielectric constant of a solid increase due to Frenkel Defect? |
In crystalline solids, an atom may be displaced from its original position in order to create a vacancy in the original location. This is referred to as a Frenkel defect. Why does this defect result in an increase of the dielectric constant of the solid? |
Why does the dielectric constant of a solid increase due to a Frenkel defect? |
For Lithium, the electronic configuration is $ 1s^2,2s^1 $. So I tried to calculate the $ Z_{eff} $ for 2s orbital of the neutral atom.
$$ Z_{eff} = Z-\sigma $$
$$ Z_{eff} = 3-(2\times0.3) $$
$$ Z_{eff} = 3-(2\times0.3) $$
$$ Z_{eff} = 2.4 $$
But the wikipedia article's table of Effective nuclear charge states... |
Does Slater's law apply to neutral Lithium(at least approximately)? |
> But I am getting the correct answer only if I take $\lambda_2$ as $2$ times the given decay constant for the second reaction. Is this because of $\underline{2}A$ on the reactant side instead of $A$?
**Yes.**
----
The way I tend to approach half-life problems is to recast them as the relevant kinetic differen... |
> But I am getting the correct answer only if I take $\lambda_2$ as $2$ times the given decay constant for the second reaction. Is this because of $\underline{2}A$ on the reactant side instead of $A$?
**Yes.**
----
The way I tend to approach half-life problems is to recast them as the relevant kinetic differen... |
For lithium, the electronic configuration is $\ce{(1s)^2(2s)^1}$. I tried to calculate $Z_{eff}$ for the $\ce{2s}$ orbital of the neutral atom as follows:
$$Z_{eff} = Z-\sigma$$
$$Z_{eff} = 3-(2\times0.3)$$
$$Z_{eff} = 2.4$$
But the Wikipedia article's table of effective nuclear charges (linked below) states th... |
Do Slater's rules apply to neutral lithium (at least approximately)? |
Find the average life of a radio nuclide which decays by parallel paths
$$A\rightarrow B$$
$$2A\rightarrow B$$
where the decay constants are $\lambda_1=0.018\ \mathrm{s}^{-1}$ and $\lambda_2=0.001\ \mathrm{s}^{-1}$, respectively.
**Attempt:**
I used the formula $$\frac{1}{t}=\frac{t_1t_2}{t_1+t_2}$$ where $t$ ... |
Do covalent always necessarily form an octet? *Always*? |
Do covalent bonds always form an octet? |
Do electrons in covalent bonds always necessarily obey the octet rule? *Always*? |
Do electrons in covalent bonds always obey the octet rule? |
In a Wurtz reaction, is the intermediate formed a carbanion or a free radical. And if can assume both mechanisms to be true, how can we decide the reactivity of a tertiary halide? |
Here's a very random introduction. I heard the term, "dirty Sprite" (it's some rap album/slang term) on a YouTube advertisement. I Googled "dirty Sprite", and it's apparently a recreational drug: codeine syrup in Sprite lemon-lime soda. People allegedly get high off of it, meaning the opiates in codeine is metabolized ... |
How does the acidity of soft drinks not affect certain drugs, such as opiates? What about drugs and stomach acid? |
Today, I bought some graphite for my pencil. It is rated HB on the [HB graphite scale][1], a measurement of the hardness of graphite. My question is how can there be different hardnesses of the same substance? Is there a difference between 4B graphite and 6H graphite on the molecular level? Are the different hardnesses... |
I've got a few very very basic questions about ionic bonds and their role in batteries.
My assumptions (correct me if I'm wrong):
- Ionic bonds occur between a metal and a non-metal (the non-metal takes
the metal's electron to fill its valence shell). Therefore the metal atoms are left with a positive charg... |
I am trying to determine the products of the ammonium nitrate and copper nitrate. Any ideas on if the below reaction is correct?
NH4NO3+ Cu(NO3)2 → Cu(NH3)4(NO3)2
Ammonium Nitrate + Copper Nitrate → Tetrammine Copper(II) Nitrate
Also, what would be the products of the other two reactions below:
Copper Nitrate ... |
Chemical Reaction Between Two Nitrates? |
It is a common observation that a concentrated solution of hydrochloric acid kept in the lab fumes. What is the chemistry behind this phenomenon? Does $\ce{HCl}$ somehow react with the moisture in the air due to its hygroscopic nature? |
Why does concentrated HCl fume? |
I am trying to determine the products of the ammonium nitrate and copper nitrate. Any ideas on if the below reaction is correct?
$$\ce{NH4NO3 + Cu(NO3)2 -> Cu(NH3)4(NO3)2}$$
Ammonium Nitrate + Copper Nitrate → Tetrammine Copper(II) Nitrate
Also, what would be the products of the other two reactions below:
- ... |
What happens when two nitrates react with each other? |
Many drugs are not very soluble in water what is a common property for a lot of organic substances, including Codeine. Therefor it is very common to turn them into their hydrochlorid which is simply $\text{Drug}\ce{.HCl}$. [[4]] E.g., Crystal Meth got it's name from the crystals that the hydrochloride forms.
$\hskip... |
I am confused about the application of Le Chatelier's principle to reaction systems. Consider the reaction: $$\rm H_2O_2 \rightleftharpoons 2\, OH\,\,\,\,\,(i)$$ to be at at equilibrium. As the pressure is increased, the reaction moves towards forming $\rm H_2O_2$ as this direction reduces the number of moles in the sy... |
I am confused about the application of Le Chatelier's principle to reaction systems. Consider the reaction: $$\rm H_2O_2 (g) \rightleftharpoons 2\, OH(g)\,\,\,\,\,(i)$$ to be at at equilibrium. As the pressure is increased, the reaction moves towards forming $\rm H_2O_2$ as this direction reduces the number of moles in... |
I am confused about the application of Le Chatelier's principle to reaction systems. Consider the reaction: $$\rm H_2O_2 (g) \rightleftharpoons 2\, OH^{.} (g)\,\,\,\,\,(i)$$ to be at at equilibrium. As the pressure is increased, the reaction moves towards forming $\rm H_2O_2$ as this direction reduces the number of mol... |
> The question asks us to select the compound with the smallest heat of
> hydrogenation per mole out of the following:
>
> So would we consider each heat of hydrogenation "per mole of hydrogen"
> or "per mole of the given compound"?
Here is some data that will help answer the question.
[![enter image descrip... |
The question asks us to select the compound with the smallest heat of hydrogenation per mole out of the following:
a) 1-butene
b) *trans*-2-butene
c) *cis*-2-butene
d) 1,3-butadiene
Since all four compounds form the same product (butane), a comparison without actual data should be possible. 1,3-butadiene... |
> The question asks us to select the compound with the smallest heat of
> hydrogenation per mole out of the following:
>
> So would we consider each heat of hydrogenation "per mole of hydrogen"
> or "per mole of the given compound"?
Here is some data that will help answer the question.
[![enter image descrip... |
When you calculate the solubility product constant for a salt and one of its hydrates, you sometimes get drastically different numbers! I don't know how this can be because they both dissociate into the same ions. For example, sodium sulfate heptahydrate $\ce{Na2SO4.(H2O)7}$ is more soluble than anhydrous sodium sulfat... |
So I watched the Crash Course chemistry video about the electron and in the video Hank showed an example configuration of Iron as 1s2 2s2 2p6 3s2 3p6 4s2 3d6 and explained that due to energy constraints, electrons go to the s orbital of the 4th shell before going into the d orbital of the 3rd shell and so they are writ... |
So I watched the Crash Course chemistry video about the electron and in the video Hank showed an example configuration of Iron as $\mathrm{(1s)^2 (2s)^2 (2p)^6 (3s)^2 (3p)^6 (4s)^2 (3d)^6}$ and explained that due to energy constraints, electrons go to the s orbital of the 4th shell before going into the d orbital of th... |
I watched the Crash Course chemistry video about the electron. In the video Hank showed an example configuration of iron as $\mathrm{(1s)^2 (2s)^2 (2p)^6 (3s)^2 (3p)^6 (4s)^2 (3d)^6}$ and explained that due to energy constraints, electrons go to the s orbital of the 4th shell before going into the d orbital of the 3rd ... |
Can someone please explain why is 8-Hydroxyquinoline in fact 8 and 1,10-phenanthroline 1 and 10? I'm counting C-atoms and just cannot see why is hydroxy in a position 8 and N-atoms in position 1 and 10. |
I am trying to perform nucleation simulations with molecular dynamics. To prepare the metastable fluid, I am equilibrating at temperatures about 30 K above the melting temperature, and then "quenching" down to a sub cooled liquid state. For those familiar with lammps, the method I am using to perform the quench is
... |
Can someone please explain why the carbon in 8-hydroxyquinoline is numbered 8, while in 1,10-phenanthroline the nitrogens are numbered 1 and 10? I'm counting carbon atoms and just cannot see why the hydroxy is in position 8 and nitrogen atoms are in positions 1 and 10. |
Here is the picture of monobasic potassium phosphate:
http://media.scbt.com/image.php?image=/i/11/46/114654.jpg
And here is the picture of dibasic potassium phosphate:
https://static.fishersci.com/images/F158513~wl.jpg
Is it possible for the phosphorous-containing anions to further break down into actual phosphates... |
Is it possible for monobasic and dibasic potassium phosphate to complete break down into phosphates? |
Note: I've been sent here from the Physics Stack Exchange, please be nice. :)
I used Huckel's method along with a Linear Combination of Atomic Orbitals (LCAO) to calculate an estimate for the orbital energies of cyclobutadiene (C4H4) and butadiene (C4H6). For butadiene, you end up with the result
E = C +/- 1.62 D... |
How can I guess the shape and phase of the molecular orbitals of butadiene (H4C6) using LCAO and Huckel's method? |
Here is the picture of monobasic potassium phosphate:
[![enter image description here][1]][1]
And here is the picture of dibasic potassium phosphate:
[![enter image description here][2]][2]
Is it possible for the phosphorous-containing anions to further break down into actual phosphates and floating protons... |
I searched a lot for this and couldn't find any answers. Is water softening a purely ratio-based equilibrium process, ie, more Na+ cations on resin than there are Ca+ cations in the water, causing most Ca+ in solution to be displaced? Or do kinetic factors come into play, where at equilibrium Ca+ cations will end up s... |
Do ion-exchange resins soften water through a kinetic equilibrium process? |
I searched a lot for this and couldn't find any answers. Is water softening a purely ratio-based equilibrium process, ie, more $\ce{Na+}$ cations on resin than there are $\ce{Ca^{2+}}$ cations in the water, causing most $\ce{Ca^{2+}}$ in solution to be displaced? Or do kinetic factors come into play, where at equilibr... |
I used Hückel's method along with a Linear Combination of Atomic Orbitals (LCAO) to calculate an estimate for the orbital energies of cyclobutadiene ($\ce{C4H4}$) and butadiene ($\ce{C4H6}$). For butadiene, I ended up with the result
$E = \alpha \pm 1.62 \beta$ and $E = \alpha \pm 0.62 \beta$,
where $\alpha$ and... |
Guess the shape and phase of the MOs of butadiene using LCAO and Hückel's method? |
This is with regard to the newly discovered 2D materials that can support electron flow like Phosphorene and Transition metal dichalcogenides. How do they conduct electricity? I also read that their electric properties change with the number of layers. For example, the band gap of black phosphorus changes from 0 - 2ev ... |
This is regarding to the newly-discovered 2-D materials that can support electron flow, such as phosphorene and transition metal dichalcogenides. How do they conduct electricity?
I also read that their electric properties change with the number of layers. For example, the band gap of black phosphorus changes from 0... |
In the case of $\ce{HNO3}$, according the abstract of [this paper][1]$^\dagger$, nitric acid vapors act as nucleation sites for ambient water, causing the mists/fumes that are observed above concentrated nitric acid solutions:
> The gas phase reaction [forming nitric acid from other reagents] supplies $\ce{HNO3}$ n... |
What is the reaction that happens betewwen Vinegar/Salt/Hydrogen peroxide as an etching solution and copper and is the residue environment friendly? |
What is the reaction that happens betewwen vinegar/salt/hydrogen peroxide as an etching solution and copper, and is the residue environment friendly? |
> a comparison without actual data should be possible. 1,3-butadiene is
> conjugated so it is the most stable compound and therefore its heat of
> hydrogenation should be the smallest
No, 1,3-butadiene is not the most stable of these compounds, either for the whole molecule or on a per double bond basis (see below... |
I searched a lot for this and couldn't find any answers. Is water softening a purely ratio-based equilibrium process, ie, more $\ce{Na+}$ cations on resin than there are $\ce{Ca^2+}$ cations in the water, causing most $\ce{Ca^2+}$ in solution to be displaced? Or do kinetic factors come into play, where at equilibrium ... |
[Diamond mining][1]
[1]: http://www.dicholding.com/en/diamond/general-informations/diamonds-mining
This link says that diamonds will stick to "anything oleaginous" and that other materials slide down the fat that is applied to an inclined plane used in the mining apparatus. I infer that the surface of the di... |
Why is it possible to use lipids to recover diamonds in mining? |
I need clarity on saturated vapour pressure in a closed system at equilibrium. How does saturated vapour pressure relate to vapour pressure? |
A vial of [pyrrole monomer][1] (that was occasionally exposed to air) changed its color while degrading from pale yellow to dark orange.
What is the mechanism of pyrrole degradation? What are the resulting products?
[1]: http://www.sigmaaldrich.com/catalog/product/aldrich/131709 |
What is the degradation mechanism of pyrrole? |
According to [the Wikipedia piece on diamonds](https://en.wikipedia.org/wiki/Diamond):
>Diamonds are naturally lipophilic and hydrophobic, which means the diamonds' surface cannot be wet by water but can be easily wet and stuck by oil. This property can be utilized to extract diamonds using oil when making synthetic... |
I have been studying alkanes, alkenes & alkenes for a while, and I see in the examples that all the basic structural formulas start with $\ce{CH3}$ then $\ce{CH2}$ and the last carbon atom is $\ce{CH3}$ but the one that is attached to the singe/double/triple bond is $\ce{CH}. (Please correct me if i'm explaining it wit... |
Trying to understand SMILES patterns? |
The title says it all, I thought it should be that the closer the two ions are, the larger the repulsive force, therefore, it should rather require less energy to take them apart (although being too far, it would have a lower melting point as well since it would have less attraction) so can anyone answer my question? I... |
Why do Ionic Compounds have Larger Melting Points/Boiling Points when they have smaller radii? |
The title says it all, I thought it should be that the closer the two ions are, the larger the repulsive force, therefore, it should rather require less energy to take them apart (although being too far, it would have a lower melting point as well since it would have less attraction) so can anyone answer my question? I... |
Why do Ionic Compounds have Larger Melting Points/Boiling Points when they have smaller radii?
I thought it should be that the closer the two ions are, the larger the repulsive force, therefore, it should rather require less energy to take them apart. (Although being too far, it would have a lower melting point as w... |
I distinctly remember a side-by-side comparison from a book where there are two nails in two beakers submerged in water. One nail had a layer of oil on top of the water, and that nail didn't rust, while the other did.
It seems that oiling iron/steel products is supposed to prevent them from rusting:
http://www.ju... |
How does oil prevent rust? |
I distinctly remember a side-by-side comparison from a book where there are two nails submerged in water, in two beakers: one nail had a layer of oil on top of the water, and that nail didn't rust; the other did.
It seems that oiling iron/steel products is supposed to prevent them from rusting:
http://www.justans... |
So we have select the set of elements which will have almost the same atomic radii
(a)O,S,Se,Te
(b)Li,Be,B,C
(c)Fe,Co,Ni,Cu
Now I goggled the atomic radii of the (c) set and found them to be extremely close, all of them were nearly 135pm(according to empirical data). Is there a specific reason for this or i... |
Why is the atomic radii of Iron,Cobalt,Nickel and Copper almost the same? |
I came across a [reaction][1] that looks as follows: <br>
[![enter image description here][2]][2] <br>
In this reaction the polyphosphate is common in both the sides of the reaction. Does this act as enzyme? But from the website it seems that the enzyme is ADP-specific glucokinase(in the enzyme section click 2.7.1.6... |
I understand thermodynamics in a physicsy way - at the level of Callen's *Thermodynamics*. However, my chemical thermodynamics is quite rusty: concepts like fugacity and activity coefficients are only vaguely familiar from undergrad courses.
I'm looking for a *well written, rigorous and succinct* guide to advanced c... |
Trying to understand SMILES(?) patterns |
So we have select the set of elements which will have almost the same atomic radii
1. O, S, Se, Te
2. Li, Be, B, C
3. Fe, Co, Ni, Cu
Now I goggled the atomic radii of the third set and found them to be extremely close, all of them were nearly 135pm(according to empirical data). Is there a specific reason fo... |
The Maxwell-Boltzmann distribution can be used to determine the fraction of particles with sufficient energy to react with a given reactant. I know that the curve applies to gaseous reactants but I would like to know whether a solid or liquid follows a similar distribution.
In other words can I use a Maxwell-Boltzma... |
Does the Maxwell Boltzmann Distribution only apply to gases? |
##Introduction
It is fairly obvious that the statement given by Wikipedia cannot be entirely correct.
> There is some evidence that the anion (which obeys the 4n+2 Hückel rule) is aromatic.
The trinitromethane anion cannot obey the [Hückel (4n+2) rule][1] because it is neither monocyclic nor planar. And assigning ... |
I am an ESL teacher, and am designing an activity to teach my engineering students the differences between the words "invention," "discovery," "innovation," and "creation," words that are often confusing for non-native speakers (and as I'm finding out, native speakers.)
I have looked on the internet for usage and it s... |
Do Chemists "discover," "invent," or "create" things? |
So we have to select the set of elements which will have almost the same atomic radii:
1. O, S, Se, Te
2. Li, Be, B, C
3. Fe, Co, Ni, Cu
Now I googled the atomic radii of the third set and found them to be extremely close, all of them were nearly 135pm (according to empirical data). Is there a specific reas... |
I am an ESL teacher, and am designing an activity to teach my engineering students the differences between the words "invention," "discovery," "innovation," and "creation," words that are often confusing for non-native speakers (and as I'm finding out, native speakers.)
I have looked on the internet for usage and it... |
Writing out the equilibrium expression for a weak acid in solution:
$$[\ce{H3O+}] = K_\mathrm a\frac{[\ce{HA}]}{[\ce{A-}]}$$
Buffers need to keep the concentration of the weak acid to its conjugate base similar in order for it be effective.
Let’s say you add a small amount of base. Some of the $\ce{HA}$ molec... |
I have a collection of old books (all 80+ years old), recently, I received a British Chemistry text from 1903 (intro page below) - this being the oldest book of my collection (112 years old):
![enter image description here][1]
One thing I notice is that there is a distinct smell that comes from the pages of olde... |
Despite very similar skeletal structure,the difference of measurement of acid strength is qu... |
Writing out the equilibrium expression for a weak acid in solution:
$$[\ce{H3O+}] = K_\mathrm a\frac{[\ce{HA}]}{[\ce{A-}]}$$
Buffers need to keep the concentration of the weak acid to its conjugate base similar in order for it be effective.
Let’s say you add a small amount of base. Some of the $\ce{HA}$ molec... |
Despite very similar skeletal structures, the difference in acid strength is quite si... |
Despite very similar skeletal structures, the difference in acid strength is quite significant... |
The Maxwell-Boltzmann distribution can be used to determine the fraction of particles with sufficient energy to react. I know that the curve applies to gaseous reactants and would like to know whether solids and/or liquids are also described by a similar distribution.
In other words, can I use a Maxwell-Boltzmann di... |
Does the Maxwell-Boltzmann distribution apply to gases only? |
Despite very similar skeletal structures, the difference in acid strength is quite significant... |
So we have to select the set of elements which will have almost the same atomic radii:
1. O, S, Se, Te
2. Li, Be, B, C
3. Fe, Co, Ni, Cu
Now I googled the atomic radii of the third set and found them to be extremely close to one another: all of them are nearly 135 pm (according to empirical data). Is there ... |
Why are the atomic radii of iron, cobalt, nickel, and copper almost the same? |
Well, I went and searched for the solubility of oxygen in water and oil, and found this summary paper on the NIST web site: ["The Solubility of Oxygen and Ozone in Liquids"](http://www.nist.gov/data/PDFfiles/jpcrd219.pdf) by Battino, Rettich and Tominaga, _J. Phys. Chem.Ref. Data._, vol 12, no. 2, 1983.
Conveniently... |
Why do ionic compounds have higher melting and boiling points despite having smaller radii?
I thought that the closer the two ions are, the larger the repulsive force, and therefore it should rather require less energy to separate them (and at further distances apart, a lower melting point is observed because there ... |
Why do ionic compounds have higher melting and boiling points despite having smaller radii? |
Not long ago, I performed a reaction between siloxene and cerium(IV) sulphate. When the two were mixed, the mixture produced an orange-yellow glow. WHy did these glow, though? What is it about the two chemicals in particular that makes this happen?
---
## Method for synthesising siloxene:
> Carefully measure out... |
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