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What is the difference between tempering and hardening metals and their end products? |
Is there a way to extract the molecular wavefunction from GAMESS output?
I know there are packages that can extract the eigenvalues or the exponents and show them as a table but that is not of much help as anyone can easily find those values in the output file by looking at the numbers.
What I am looking for i... |
How to extract wavefunction from GAMESS output? |
Na2CO3 is deliquescent in nature, and NaHCO3 is not, for example, so Na2CO3 should have been more soluble than NaHCO3 in water (NaHCO3 I always thought was less soluble since it precipitated easily in the Solvay process). But my book says Na2CO3 is less soluble than NaHCO3 in water. Isn't deliquescence though an indica... |
Are all deliquescent salts highly soluble? |
$\ce{Na2CO3}$ is deliquescent in nature, and $\ce{NaHCO3}$ is not, for example, so $\ce{Na2CO3}$ should have been more soluble than $\ce{NaHCO3}$ in water ($\ce{NaHCO3}$ I always thought was less soluble since it precipitated easily in the Solvay process). But my book says $\ce{Na2CO3}$ is less soluble than $\ce{NaHCO3... |
I was presented with the following information:
If iron is painted, then oxygen and water are prevented from contacting the metal, and corrosion is avoided.
Sometimes the iron is coated with a thin layer of another metal, such as Tin (the layer of Tin keeps oxygen and water away from the iron)
If the layer of Tin... |
Why are the axial bonds of PF5 longer than those of the equatorial bonds? (Hybridization) |
For example, Barium Hydrogen Phosphate has acidity of 2 and basicity 1. Why does this so? Basicity is 1 because it has 1 replaceable hydrogen ion. But why does this have acidity? |
Why does an acid salt possess acidity as well as basicity? |
Does stereochemistry play any role in the heating of Cyclohexane-1,2-diol?
If I remember correctly, different products are formed depending on whether the diol is cis or trans. (I think the products are cyclohexanone and cyclopentanecarbaldehyde). Please clarify this along with the reason why different products are ... |
I am trying to obtain a PES for N2+N combination using scan feature of Gaussian. I have tried different combinations of basis sets and methods but unfortunately at some point in the iteration, the convergence criteria is not met and I get an "Aborted Core dump" closure in the log file. The Gaussian code is:
(hash) H... |
Is there a porous thin material (e.g. filter paper, membrane) that will cool a stream of air passed through it to an even cooler temperature on the other side? If this material is absorbent, could there be a chemical absorbed into the material to facilitate the cooling?
|
Is there a porous thin material that will cool a stream of air passed through it to an even cooler temperature on the other side? |
I am trying to obtain a potential energy surface (PES) for $\ce{N2 + N}$ combination using `scan` feature of Gaussian. I have tried different combinations of basis sets and methods but unfortunately at some point in the iteration, the convergence criteria is not met and I get an "Aborted Core dump" closure in the log f... |
Molecules must be within a certain distance for a reaction to begin as well as satisfying a myriad of other factors. Whilst the exact distance varies from reaction to reaction, is their any distance/molecular radius which provides a fairly good picture in terms of how close the centre of the molecules have to be to beg... |
What radius best represents reaction distance? |
Quick question: Any one knows a resource for ***Cohesive Energy Density*** of some organic materials ?
I am not looking for any specific molecule, actually I want to plan my project based on available data. I have found some tables for internal cohesive pressure but could not find any thing for CED.
Anything i... |
A *Clemmensen* reduction of a 1,3-diketone probably isn't the best idea. The reduction is likely to proceed via a ketyl radical.
![enter image description here][1]
In the case of a 1,3-diketone, formation of a dihydroxy cyclopropane, which undergoes opening/rearrangement cannot be excluded.
This reaction has... |
A *Clemmensen* reduction of a 1,3-diketone probably isn't the best idea. The reduction is likely to proceed via a ketyl radical.
![enter image description here][1]
In the case of a 1,3-diketone, formation of a dihydroxy cyclopropane, which undergoes opening/rearrangement cannot be excluded.
This reaction has... |
What is the net ionic equation of sodium hydroxide when it dissolves in water?
For the net ionic equation I got
$$\ce{NaOH(s) + H2O(l) -> NaH+(aq) + OH- (aq) + H2O(l)}$$
but it was wrong.
Then I tried:
$$\ce{NaOH(aq) -> Na+(aq) + OH- (aq)}$$
and it was wrong as well.
Can someone please explain?
|
Do you know any mathematical model of a chemical process such that it satisfies the following equations ?
$$\mathrm{u_t=a(t)u_{xx}},\,\,\,0<x<1,\,\,\,t>0$$
$$\mathrm{-ku_x(0,t)=hu(0,t)},\,\,\,t>0$$
$$\mathrm{u(1,t)=u_0},\,\,\,t>0$$
where $a(t)>0$ is time-dependent thermal diffusivity, $k>0$ constant thermal condu... |
Apologies in advance as I am not a science person by any definition. By most, I'm probably not a person but we'll let that be.
I am studying the notion of "change" in things and focusing on chemical change. Could someone please let me know if:
1. the change in the color of a photogray (photosensitive, photochromi... |
What is the graph of carbon dioxide (CO2) content in the air in a compartment consisting of 80 percent air and 20 percent ocean sea water as a function of temperature, in the temperature range 0 to 80 degree Celsius?
Example but not the complete answer:
![enter image description here][1]
As can be seen from th... |
What is the CO2 content in the air in a compartment of air and sea water, as a function of temperature? |
What is the graph of carbon dioxide ($\ce{CO2}$) content in the air in a compartment consisting of 80 percent air and 20 percent ocean sea water as a function of temperature, in the temperature range 0 to 80 degree Celsius?
Example but not the complete answer:
![enter image description here][1]
As can be seen ... |
What is the graph of carbon dioxide ($\ce{CO2}$) content in the air in a compartment consisting of 80 percent air and 20 percent ocean sea water as a function of temperature, in the temperature range 0 to 80 degree Celsius?
Example but not the complete answer:
![enter image description here][1]
As can be seen ... |
Consider the initial boundary value problem
$$u_t=a(t)u_{xx},\,\,\,0<x<1,\,\,\,t>0$$
$$-ku_x(0,t)=hu(0,t),\,\,\,t>0$$
$$u(1,t)=u_0,\,\,\,t>0$$
$$u(x,0)=f(x),\,\,\,t>0$$
where $a(t)>0$ is time-dependent thermal diffusivity, $k>0$ constant thermal conductivity and $h>0$ constant heat transfer coefficient.
-I w... |
What is the CO2 content in the air in a compartment of air and water, as a function of temperature? |
What is the graph of carbon dioxide ($\ce{CO2}$) content in the air in a compartment consisting of 80 percent air and 20 percent ocean sea water as a function of temperature, in the temperature range 0 to 80 degree Celsius?
Example but not the complete answer:
![enter image description here][1]
As can be seen ... |
Apologies in advance as I am not a science person by any definition. By most, I'm probably not a person but we'll let that be.
I am studying the notion of "change" in things and focusing on chemical change. Could someone please let me know if:
1. the change in the color of a photogray (photosensitive, photochromi... |
What is the graph of carbon dioxide ($\ce{CO2}$) content in the air in a compartment consisting of 80 percent air and 20 percent ocean sea water as a function of temperature, in the temperature range 0 to 60 degree Celsius?
Example but not the complete answer:
![enter image description here][1]
As can be seen ... |
What is the graph of carbon dioxide ($\ce{CO2}$) content in the air in a compartment consisting of 80 percent air and 20 percent ocean sea water as a function of temperature, in the temperature range 0 to 60 degree Celsius?
Example but not the complete answer:
![enter image description here][1]
As can be seen ... |
![enter image description here][1]
Could someone help me determining the aromaticity of the compounds?
My Attempt:
(i) not an aromatic compound since it only has 4 pi electrons that does not satisfy Huckels (4n+2) rule
(ii) not aromatic because it only has 4 pi electrons, however im not sure if the oxygen c... |
Determining Aromaticity? |
> What activation energy would lead to a doubling in the reaction rate
> for a 10 degree increase in temperature, using the Arrhenius equation?
You’re right it is not generally true. Let’s set up an equation to solve the problem.
The Arrhenius equation is
$$k=A\operatorname{e}^{\frac{-E_\text{a}}{RT}}$$
In t... |
![enter image description here][1]
Rhodamine is a fluorescent dye. What features of the molecule result in it being so highly fluorescent ?
I assume the extended conjugated system with a stabilized first excited state is necessary, to absorb light in the visible region of the spectrum, and I would also think a r... |
Apologies in advance as I am not a science person by any definition. By most, I'm probably not a person but we'll let that be.
I am studying the notion of "change" in things and focusing on chemical change. Could someone please let me know if:
1. the change in the color of a photogray (photosensitive, photochromi... |
(i) that's correct
(ii) is aromatic, it fit's the 4n+2 rule with n=1. Here is a drawing of furan showing 2 lone pair electrons in a p-orbital that completes the cyclic aromatic ring. Furan's other lone pair of electrons is perpendicular to the pi system and does not play a role in furan's aromaticity.
![enter im... |
Preface: Buffer solution (acid-base buffer). I am provided with a weak base, which I will designate B. pKa for B's conjugate acid--which I will designate BH--is 8.1, and its mole weight (sic) is 121.1. I'm assuming the latter is the molar mass, though I don't know how that helps me solve this problem.
Problem: 0.1 M... |
I cannot figure out why glycine hydrochloride is more acidic than chloroacetic acid. Could I have figured this out from a pKa table and maybe am just not seeing it? On the table I have in my book (Organic Chemistry, Seyhan Ege, 3rd ed) , neither acid nor its conjugate base are there.
Thanks! |
Why is glycine hydrochloride more acidic than chloroacetic acid? |
I had a conversation with somebody who had somewhat confused ideas about food. He thought that "all food contains sugar" and when I gave a bottle of oil as the counterexample, he said the glycerol is the sugar there.
Now let's forget for a minute that glycerol is not a sugar. The point is, glycerol is indeed a "bui... |
I have to build the stability diagram of mercury and I have a problem with this couple :
$Hg^{2+}/Hg_2^{2+}$ $E^°=0.91V$
Exercise says that a the border the concentration is $C=0.10 mol.L^{-1}$ for all ions.
So I have : $2Hg^{2+}+2e^- = Hg_2^{2+}$
Then by Nernst relation I have : $E=E^°+0.03\times \log\le... |
I have to build the stability diagram of mercury and I have a problem with this couple :
$Hg^{2+}/Hg_2^{2+}$ $E^°=0.91V$
Exercise says that a the border the concentration is $C=0.10 mol.L^{-1}$ for all ions.
So I have : $2Hg^{2+}+2e^- = Hg_2^{2+}$
Then by Nernst relation I have : $E=E^°+0.03\times \log\le... |
I am trying to figure out the hazard quotient of copper compared to the standard. The standard for drinking water is 1300 mg/l and the first area has a value of 837 ug. How do I convert this?
I use the formula hq (hazard quotient) = contaminant (c) divided by standard (s).
or HQ= C/S. I am having problems with t... |
I am trying to figure out the hazard quotient of copper compared to the standard. The standard for drinking water is $1300 \frac{mg}{l}$ and the first area has a value of $837 \mu g$. How do I convert this?
I use the formula hq (hazard quotient) = contaminant (c) divided by standard (s).
or $$HQ= \frac{C}{S}$$. ... |
I am trying to figure out the hazard quotient of copper compared to the standard. The standard for drinking water is 1300 mg/l and the first area has a value of 837 µg. How do I convert this?
I use the formula hq (hazard quotient) = contaminant (c) divided by standard (s).
or $$HQ= \frac{C}{S}$$ I am having probl... |
What is a catemer and how does it differ from a dimer? What type of compounds could form catemers and how does their formation influence its crystal structure? |
What is a catemer? |
What is the chemical reaction through which propylene glycol/glycerin forms formaldehyde/acetaldehyde?
1. Propylene glycol is NOT the same as glycerin. Propylene glycol does not decompose on heating, it simply boils. In theory, under certain conditions (pressure/encapsulation/catalysts) it could dehydrate to either ... |
For example, $\ce{BaHPO_{4}}$ has acidity of 2 and basicity 1.
1. Why does this so? Its basicity is 1 because it has 1 replaceable hydrogen ion.
2. But why does this have acidity? |
Would isolated silicon engage in network covalent bonding as carbon does or would it engage in a different kind of bonding? Would germanium display similar qualities? |
What type of bonding occurs in isolated silicon? |
Given a forward reaction with positive enthalpy, is its reverse reaction be endothermic or exothermic? |
Would isolated silicon engage in network covalent bonding as quartz does or would it engage in a different kind of bonding? Would germanium display similar qualities?
*I am asking what is the bonding of silicon, not why silicon is different from carbon.
*I am interested in isolated silicon, not silicon as a "hydr... |
First I should say I never have done any spectroscopies and I am just reading about it.
As long as I know, uv/vis spectrophotometer has 2 beam samples: **sample** and **reference**. The sample has very diluted test material in a solvent and the reference is only the solvent.
I was reading a book about some expe... |
What is reference material in spectrophotometry? |
First, I should say I never have done any spectroscopies and I am just reading about it.
As far as I know, UV-Vis spectrophotometer has 2 beam samples: **sample** and **reference**. The sample has very diluted test material in a solvent and the reference is only the solvent.
I was reading a book about some expe... |
What is this reference material in spectrophotometry? |
> As the reference is the solvent alone, does it mean the samples are dilute solutions in water ? if so, how they solved benzene in water?
I come to a different conclusion.
To me it reads as follows:
- sample: **solution** of benzene, acetone, acetonitrile, etc. **in** water
- reference: water
Benzene ... |
Is ln(K2/K1) = (∆h°rxn/R)(1/T1 - 1/T2) even when ∆h°rxn varies strongly with temperature? |
What kinds of molecules will experience hydrogen bonding (inter and intra)? Why does it occur for some H atoms but not others? |
When does hydrogen bonding happen? |
> As the reference is the solvent alone, does it mean the samples are dilute solutions in water ? if so, how they solved benzene in water?
I come to a different conclusion.
To me it reads as follows:
- sample: **solution** of benzene, acetone, acetonitrile, etc. **in** water
- reference: water
Benzene ... |
Consider ethanedioic acid:
![enter image description here][1]
Could it form intramolecular hydrogen bonds (between the C=O and HO)?
![enter image description here][2]
[1]: https://i.stack.imgur.com/C6Xtum.jpg
[2]: https://i.stack.imgur.com/Xpjibm.jpg |
Does intramolecular hydrogen bonding occur in dicarboxylic acids? |
What is the chemical reaction through which propylene glycol/glycerin forms formaldehyde/acetaldehyde?
1. Propylene glycol is NOT the same as glycerin. Propylene glycol does not decompose on heating, it simply boils. In theory, under certain conditions (pressure/encapsulation/catalysts) it could dehydrate to either ... |
I am learning about solution and while giving example of liquid(solute) and solid(solvent) my teacher told Mercury forms amalgam with all the metals except iron.
I want to know why it is so?
****
P.S. I tried to find this on S.E. but i could not find it. |
I am learning about solutions and while giving an example of a liquid (solute) and a solid (solvent), my teacher told us that mercury forms an amalgam with all the metals except iron.
I want to know why this is so?
****
P.S. I tried to find this on S.E. but I could not find it. |
Why does mercury not form amalgam with iron? |
On a proton NMR, does the hydrogen in the CHO group cause coupling, or get coupled itself? Specifically, I a considering 2-methylpropanal. I cannot decide whether the H in the aldehyde group would be split into a doublet or remain as a singlet, and I am unsure as to whether the single proton on carbon number two would ... |
Spins spin coupling on proton NMR for an aldehyde? |
> What kinds of molecules will experience hydrogen bonding (inter and intra)?
**Intramolecular hydrogen bonds:**
- The hydrogen bond which is within the same molecules is called intramolecular hydrogen bond.
- It will form when 2 functional group of a molecule can form hydrogen bonds with each other.
- I... |
> What kinds of molecules will experience hydrogen bonding (inter and intra)?
**Intramolecular hydrogen bonds:**
- The hydrogen bond which is within the same molecules is called intramolecular hydrogen bond.
- It will form when 2 functional group of a molecule can form hydrogen bonds with each other.
- I... |
> I cannot decide whether the H in the aldehyde group would be split into a doublet or remain as a singlet […]
What would be the argument **against** $^3J$ coupling between these protons? The aldehyde proton will appear as a doublet.
Don't forget that coupling works both ways! $\ce{(CH3)2C\color\red{H}-}... |
If electrons were spin-$\frac {3}{2}$
instead of spin-$\frac {1}{2}$ ,
what would be the atomic
number $Z$ for the first noble gas ?
|
What is the graph of carbon dioxide ($\ce{CO2}$) content in the air in a compartment consisting of 80 percent air and 20 percent ocean sea water as a function of temperature, in the temperature range 0 to 60 degree Celsius?
Example but not the complete answer:
![enter image description here][1]
As can be seen ... |
C4H6O2 (10.75g) was dissolved in water (250cm3) and then a 20cm3 sample was titrated against an alkali metal hydroxide solution. This required 17.35cm3 of the alkali. What was the concentration of the alkali?
The water was evaporated from the alkali solution (100cm3) to leave a white solid (3.23g). Identify the alkal... |
$\ce{C4H6O2}$ (10.75g) was dissolved in water (250cm<sup>3</sup>) and then a 20cm<sup>3</sup> sample was titrated against an alkali metal hydroxide solution. This required 17.35cm<sup>3</sup> of the alkali. What was the concentration of the alkali?
The water was evaporated from the alkali solution (100cm<sup>3</sup>)... |
$\ce{C4H6O2}$ (10.75 g) was dissolved in water (250 cm<sup>3</sup>) and then a 20 cm<sup>3</sup> sample was titrated against an alkali metal hydroxide solution. This required 17.35 cm<sup>3</sup> of the alkali. What was the concentration of the alkali?
The water was evaporated from the alkali solution (100 cm<sup>3</... |
I have a device in a box which has parts of metal. So can I prevent corrosion by creating a vacuum around the metallic object?
|
Can we prevent metal corrosion by creating a vacuum around it? |
> What kinds of molecules will experience hydrogen bonding (inter and intra)?
**Intramolecular hydrogen bonds:**
- The hydrogen bond which is within the same molecules is called intramolecular hydrogen bond.
- It will form when 2 functional group of a molecule can form hydrogen bonds with each other.
- I... |
$\ce{C4H6O2}$ (10.75 g) was dissolved in water (250 cm<sup>3</sup>) and then a 20 cm<sup>3</sup> sample was titrated against an alkali metal hydroxide solution. This required 17.35 cm<sup>3</sup> of the alkali. What was the concentration of the alkali?
The water was evaporated from the alkali solution (100 cm<sup>3</... |
As a contact lenses user, I was looking for information about which polymer is better for contact lenses. Ionic or non-ionic?
It's very hard to find credible and non-biased info about contact lenses on the internet so I remembered to ask here. |
Which polymers are better for contact lenses? Ionic or non ionic? |
I got this problem in school as a tool to get ready for International Chemistry Olympiad, but I have some problems with this challenge.
So, the problem is to calculate as precise as possible the Gibbs free energy for $\ce{CaCO3}$ decomposition at 1200 K.
I know that $\mathrm{d}G=\mathrm{d}H-T\cdot\mathrm{d}S$.
B... |
I dont know if this is really applicable but I want to add a custom force ( say F(x,y,z) ) to some atoms in my geometry optimization. Is there any way to add such forces to the DFT calculation? ( preferably GAMESS or Gaussian)
Let me bring an example. Say I have molecule A and molecule B and a force that changes in ... |
How to define custom force in quantum chemistry packages? |
Can somebody explain as concrete as possible, how the change of **temperature** and the change of **pH** leads to deviations of this law? |
If one took equal moles of Lithium and Potassium compounds in equal volume of solution, which would have higher conductivity? Is it the same for molar conductivity?
Say, LiCl and KCl, of a litre each. Also, as Molar Conductivity = Conductivity / Molarity , are molar conductivity and conductivity directly proportional... |
Hmmm, I can't think of much else. You have a conjugated, planar and rigid structure that ensures your structure doesn't change/expand much upon promotion of an electron into the antibonding orbital; hence, ensuring a good FC factor.
Possibly solvent related effects that might encourage ISC over fluoresence? I know p... |
Could someone please show me the MO diagram for $N_2^{2-}$? What I did was since N has 5 valence $e^{-}$, then $N_2$ must have 10, and $N_2^{2-}$ must have 12. And N has $s$ and $p$ orbital mixing. So when I draw out the MO it has all the orbitals filled. And the bond order is $\frac{1}{2}(6-6)=0$, but this is apparent... |
As a contact lenses user, I was looking for information about which polymer is better for contact lenses. Ionic or non-ionic?
It's very hard to find credible and non-biased info about contact lenses on the internet so I remembered to ask here.
Edit:
Normally I use Biomedics 55 (Ocufilcon D - ionic) or Softlens 5... |
We had this question in a test and I am not sure of the answer
>**Q.** Temperature changes don't effect the extent of inter and intra molecular hydrogen bonding. State true or false.
I think that raising temperature would increase the kinetic energy of molecules and would thus lead to weakening of *inter* molecul... |
As a contact lenses user, I was looking for information about which polymer is better for contact lenses. Ionic or non-ionic?
It's very hard to find credible and non-biased info about contact lenses on the internet so I remembered to ask here.
Edit:
Normally I use Biomedics 55 (Ocufilcon D - ionic) or Softlens 5... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/R3bb7.png
Today our teacher told us that the following carbocation rearrangement occurs due to back bonding.I could not really follow what he meant.Can someone please explain **what** is actually happening during the following carbocation rearr... |
If one took equimolar solutions of $\ce{Li}$ and $\ce{K}$, which would have higher conductivity? Is it the same for molar conductivity?
Say, $\ce{LiCl}$ and $\ce{KCl}$, of a litre each. Also, as Molar Conductivity = Conductivity / Molarity, are molar conductivity and conductivity directly proportional? Why or why no... |
According to wikipedia, the third law of thermodynamics is "The entropy of a perfect crystal, at absolute zero (zero kelvins), is exactly equal to zero.".
Then, theoretically, could all substances, including molecular compounds, theoretically attain absolute zero? Another way of thinking of this question is whether ... |
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