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I'm wondering why radium appears to buck the general trend that first ionisation energies decrease as you move down a group in the periodic table: barium (the group 2 element preceding it) has a first ionisation energy of 502.9 kJ/mol, whereas radium has a slightly higher first I.E. of 509.3 kJ/mol (from the [Wikipedia... |
Why does radium have a higher first ionisation energy than barium? |
The LSPR properties of nanoparticles depend on a number of factors, including shape, size, material, crystal structure, dielectric environment, etc. However, it has been consistently shown that shape and size have the greatest effect on the optical properties of nanoparticles. Exactly WHY, however, is this true? Does a... |
Why do shape and size have the greatest effect on the optical properties of nanoparticles? |
As Surface Plasmon Resonance phenomenon is mainly seen in metal nanoparticles, i dont know whether this answer will help you?. The size dependant optical phenomenon of semiconductor nanoparticles (eg CdS) can be explained using [effective mass approximation model][1].
![enter image description here][2]
where r is ... |
If I used chloralkali electrolysis of brine to produce hydrogen, and can't use the other products (or not all of them), what route(s) can I take to revert them back to brine?
If I just mix them, I get sodium chlorate or hypochlorite. Can I process those further?
Routes that allow retrieval of some of the energy a... |
How can I dispose of chlorine and sodium hydroxide as NaCl and H2O? |
If I used chloralkali electrolysis of brine to produce hydrogen, and can't use the other products (or not all of them), what route(s) can I take to revert them back to brine?
With the $H_2$ taken away, the remaining products are:
$2 NaOH + Cl_2$
If I just mix them, I get sodium chlorate or hypochlorite. Can I ... |
If I used chloralkali electrolysis of brine to produce hydrogen, and can't use the other products (or not all of them), what route(s) can I take to revert them back to brine? I figured, since I have to put in energy to take the brine apart, it should have some desire to reform.
With the $H_2$ taken away, the remaini... |
As Surface Plasmon Resonance phenomenon is mainly seen in metal nanoparticles, I don't know whether this answer will help you? The size dependent optical phenomenon of semiconductor nanoparticles (e.g., $\ce{CdS}$) can be explained using the [effective mass approximation model][1].
![enter image description here][2... |
If I used chloralkali electrolysis of brine to produce hydrogen, and can't use the other products (or not all of them), what route(s) can I take to revert them back to brine? I figured, since I have to put in energy to take the brine apart, it should have some desire to reform.
With the $H_2$ taken away, the remaini... |
Fine, **[here's][2]** my data taken from the reference mentioned in my above comment.
I cannot vouch for it's accuracy.
This is in the `.csv` file format for its wide use as enlightened by **[Richard Terrett][1]**. You can combine certain ranges from this csv/spreadsheet to the one prepared by Richard, because it ... |
I have been intrigued by one of the principles of chemistry lately- electrolysis. In my knowledge, electrolysis is a quite dangerous operation as the decomposition of water produces hydrogen and oxygen gas, both which are flammable. However, its potent to be volatile isn't what I am concerned with; rather, it is the pr... |
How can I produce hydrogen gas efficiently and cheaply? |
I'm looking for a software which can solve chemical equations. For example something like this (given with result):
\begin{align}
\ce{CH4 + 2O2 & → CO2 + 2H2O} \\
\ce{C3H6 + HCl & → C3H7Cl}
\end{align}
Is there are such software? I'm studying chemistry as a hobby and want to check if I'm doing the reac... |
Could you please explain how the bent molecular geometry of water is due to hydrogen bonding? I was under the impression that it was because of the lone pairs. |
To be more specific, could the carbon dioxide fumes produced in the reaction be harmful to a small child? I don't have a strong background in chemistry, and I was prompted to ask this question when it was suggested by a friend that a mixture of 2 cups of vinegar and baking soda is commonly used to euthanize rodents. I'... |
Is the vinegar and baking soda experiment safe for children? |
Could you please explain how the bent molecular geometry of water is due to hydrogen bonding? I was under the impression that it was because of the lone pairs (VSEPR Theory). |
In multiple sources, e.g. http://www.phy.cuhk.edu.hk/course/surfacesci/mod3/m3_s4.pdf, I found the information that the kinetic energy $E_k$ measured using (Ultraviolet / X-ray) Photoelectron Spectroscopy is given by:
$E_k = h\nu - B.E._F - \phi_{spec}$
where $h\nu$ is the energy carried by the incident photon, ... |
In multiple sources ([example](http://www.phy.cuhk.edu.hk/course/surfacesci/mod3/m3_s4.pdf)), I found the information that the kinetic energy $E_k$ measured using (Ultraviolet / X-ray) Photoelectron Spectroscopy is given by:
$E_k = h\nu - B.E._F - \phi_{spec}$
where $h\nu$ is the energy carried by the incident p... |
I have a first-order reaction of the form: $k_f = k_1 (M*s)^{-1}$. What happens at infinite concentration? Do we need to measure additional kinetics parameters in this regime? |
I have a first-order reaction of the form: $k_f = k_1 (M*s)^{-1}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry? Do we need to measure additional kinetics parameters in this regime? |
I have a first-order reaction, for the binding of two molecules, of the form: $k_f = k_1 (M*s)^{-1}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry, and is it ever the case that $k_f > k_1$? Do we need to measure additional kinetics parameters in thi... |
I have a first-order reaction, for the binding of two molecules, of the form: $k_f = k_1 (M*s)^{-1}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry, and is it ever the case that $k_f > k_1$? Do we need to measure additional kinetics parameters in thi... |
I have a first-order reaction, for the binding of two molecules, of the form: $\text{k}_\text{f} = \ce{k_1 (M*s)^{-1}}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry, and is it ever the case that $\text{k}_\text{f} > \text{k}_\text{1}$? Do we need t... |
I have a first-order reaction, for the binding of two molecules, of the form: $\text{k}_\text{f} = \ce{k_1 (M*s)^{-1}}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry, and is it ever the case that $\text{k}_\text{f} > \text{k}_\text{1}$? Do we need t... |
I have a first-order reaction, for the binding of two molecules, of the form: $\text{k}_\text{f} = \ce{k_1 (M*s)^{-1}}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry? Do we need to measure additional kinetics parameters in this regime?
If anyone ... |
I have a first-order reaction, for the binding of two molecules, of the form: $\text{k}_\text{f} = \ce{k_1 (M*s)^{-1}}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry? Do we need to measure additional kinetics parameters in this regime?
If anyone ... |
What could be the possible basis set that can be used for a metal base macrocyclic complex in gaussian09? I am using transition metals such as Ni,Co etc,also i have tried using dft and hf theory for optimization but not getting appropriate results. |
I have a first-order reaction, for the binding of two molecules, of the form: $\text{k}_\text{f} = \ce{k_1 (M*s)^{-1}}$. What happens at infinite concentration? How is this upperbound typically handled for approximations in chemistry? Do we need to measure additional kinetics parameters in this regime?
If anyone ... |
What could be the possible basis set that can be used for a metal base macrocyclic complex in gaussian09?
I am using transition metals such as $\ce{Ni}$, $\ce{Co}$, etc. Also, I have tried using DFT and HF theory for optimization but I am not getting appropriate results. |
I expected ethene to undergo electrophilic substitution due to $\ce{HCN}$ but it doesn't happen,as told by my textbook.i couldn't figure out the reason; as I found out that $\ce{HCN}$ does react with $\ce{CH3CH2Br}$ by nucleophilic substitution.upon ionisation,the proton of $\ce{HCN}$ is an electrophile,while the cyani... |
Why cannot HCN react with ethene? |
What could be the possible basis set that can be used for a metal base macrocyclic complex in gaussian09?
I am using transition metals such as $\ce{Ni}$, $\ce{Co}$, etc. Also, I have tried using DFT and HF theory for optimization but I am not getting appropriate results.
I am basically looking for binding of meta... |
I expected ethene ($\ce{C2H4}$) to undergo electrophilic substitution due to $\ce{HCN}$ but it doesn't happen, as I am told by my textbook.
I couldn't figure out the reason, as I found out that $\ce{HCN}$ does react with $\ce{CH3CH2Br}$ by nucleophilic substitution. Upon ionisation, the proton of $\ce{HCN}$ is an e... |
Sulphur has 6 electrons in it's outermost shell, while even oxygen has 6 electron's in it's outer shell. Since both need just 2 electrons to stabilize , why doesn't just one atom of oxygen react with one sulphur atom, forming Sulfur monoxide(SO) instead of sulfur dioxide(SO2)? |
Why does sulphur and oxygen form sulphur dioxide? |
Sulphur has 6 electrons in its outermost shell, while even oxygen has 6 electrons in its outer shell. Since both need just 2 electrons to stabilize, why doesn't just one atom of oxygen react with one sulphur atom, forming Sulfur monoxide(SO) instead of sulfur dioxide(SO2)? |
The conversion of sulphur dioxide to sulphur trioxide in the contact process for the manufacture of sulphuric acid requires the following condition:
- **Temperature**: 450 degrees
- **Pressure**: 1-2 atm , although High pressure would fasten the reaction, creating those pressures is not economical
- Vanadium Pen... |
Why does the conversion of SO2 to SO3 require high pressure? |
The conversion of sulphur dioxide to sulphur trioxide in the contact process for the manufacture of sulphuric acid requires the following condition:
- **Temperature**: 450 degrees
- **Pressure**: 1-2 atm, although High pressure would fasten the reaction, creating those pressures is not economical
- Vanadium Pent... |
Why does the conversion of $\ce{SO2}$ to $\ce{SO3}$ require high pressure? |
What could be the possible basis set that can be used for a metal base macrocyclic complex in gaussian09?
I am using transition metals such as $\ce{Ni}$, $\ce{Co}$, etc. Also, I have tried using DFT and HF theory for optimization but I am not getting appropriate results.
I am basically looking for binding of meta... |
What could be the possible basis set that can be used for a metal base macrocyclic complex in gaussian09?
I am using transition metals such as $\ce{Ni}$, $\ce{Co}$, etc. Also, I have tried using DFT and HF theory for optimization but I am not getting appropriate results.
I am basically looking for binding of me... |
Why most of chemical elements starts with -um for both organic and synthetic elements? |
Why most of chemical elements starts with -um? |
Why most of chemical elements starts with -ium for both organic and synthetic elements? |
Why most of chemical elements starts with -ium? |
Why most of chemical elements starts with -ium for both primordial and synthetic elements? |
In the section about fuels, my textbook mentions that the boiling and freezing-point of the alkanes (which are apolair) increases with an increasing molecule mass due to the london dispersionforces. Now, I understand what these are and why they become relevant when talking about apolair molecules, but I can't figure ou... |
Why does the boiling and freezing-point of apolair molecules rise with increasing molecule-mass? |
Why do the names of most chemical elements start with -ium for both primordial and synthetic elements? |
Why do the names of most chemical elements start with -ium? |
Why do the names of most chemical elements end with -ium for both primordial and synthetic elements? |
Why do the names of most chemical elements end with -ium? |
To expand on @BelieveInvis's answer -- in the early 19th century, when the Royal Society was really in the swing of things, the dominant language of scholarship was still Latin. Since Latin didn't have words for the new metallic elements, new words were coined from the existing terms for the substances and given Latina... |
I'm partnered with a jewelry production company whose plating baths require KOH. We're located in Indonesia, where import fees are absurdly high, and reliable suppliers are rare. A local shop sells KOH at \$5 / Kg, but whatever impurities are present in their mix cause enough problems to spoil the entire bath. (Expensi... |
What is the process for purifying KOH? |
In the section about fuels, My textbook mentions that the boiling and freezing-point of the alkanes (which are non-polar) increases with an increase in molecular mass due to the London dispersion forces.
Now, I understand what these are and why they become relevant when talking about non-polar molecules, but I can't... |
Why does the boiling and freezing-point of non-polar molecules rise with increasing molecular mass? |
In the section about fuels, my textbook mentions that the boiling and freezing-points of alkanes (which are non-polar) increase with an increase in molecular mass due to London dispersion forces.
Now, I understand what these are and why they become relevant when talking about non-polar molecules, but I can't figur... |
I'm wondering about how does the litmus solution work as a pH indicator.
And another question:
When you put drops of litmus solution into an colorless acid (e.g. HCl), it turns red. But then if you add colorless base (e.g. NaOH) to the mixture, it turns blue. How come?
I thought that the litmus solution doesn'... |
How does the litmus pH indicator work? |
This explanation is true for most organic indicators. Litmus is a complex mixture of organic molecules. The molecule responsible for the color change (the *chromophore*), is *7-hydroxyphenoxazone* (image taken from Wikipedia, public domain):
![7-hydroxyphenoxazone][1]
See that $OH$ group at the lower left? Tha... |
Is diamond an allotrope or polymorph of carbon? When is something considered an allotrope vs a polymorph? |
Is diamond an allotrope or polymorph of carbon? |
1. You are correct on atomic size being due to number of electrons
and their *shells* and the reason why atomic size decreases from
right to left is due to the attraction of the protons being greater
on the right than on the left.
2. The concept you are forgetting is
Valence Electrons(http://en.w... |
1. You are correct on atomic size being due to number of electrons
and their *shells* and the reason why atomic size decreases from
left to right is due to the number of the protons being greater
on the right than on the left of the periodic table with same number of shells due to shell theory(http://en... |
The conversion of sulphur dioxide to sulphur trioxide in the contact process for the manufacture of sulphuric acid requires the following condition:
- **Temperature**: 450 degrees
- **Pressure**: 1-2 atm, although High pressure would fasten the reaction, creating those pressures is not economical
- Vanadium Pent... |
Why does the conversion of SO₂ to SO₃ require high pressure? |
Why do the names of most chemical elements end with -um or -ium for both primordial and synthetic elements? |
Why do the names of most chemical elements end with -um or -ium? |
1. You are correct on atomic size being due to number of electrons
and their *shells* and the reason why atomic size decreases from
left to right is due to the number of the protons being greater
on the right than on the left of the periodic table with same number of shells due to shell theory. [(Refere... |
I am trying to generate a phase diagram of pressure versus temperature in a NPT ensemble using molecular dynamics method. I am using the Lennard Jones potential with 108 particles and Berendsen thermostat and barostat to fix the parameter.
In order to observe phase transition I plot the radial distribution function ... |
I am trying to generate a phase diagram of pressure versus temperature in a NPT ensemble using molecular dynamics method. I am using the Lennard Jones potential with 108 particles and Berendsen thermostat and barostat to fix the parameter.
In order to observe phase transition I plot the radial distribution function ... |
What is the oxidation state of Calcium found in human teeth? |
What is the oxidation state of Calcium in teeth? |
A paper says the following,
> Dichloroglyoxime was prepared by chlorination of glyoxime in 10 % HCl at 0 deg C and crystallized from toluene.
When they say "crystallized from toluene" do they unambiguously mean recrystallized from boiling toluene at standard pressure? Thermally these compounds are unstable and in... |
Why cannot HCN react with ethene?(solved) |
Yes, diamond filters are used. Usually in the filtration of ethanol and water (vodka). All drinkable ethanol must be filtered through specialized carbon filters. So in the thinking that diamonds are formed from compressed carbon, therefore a diamond filter is the extreme sports of filtration. Whether it's better? I don... |
Why cannot HCN react with ethene? |
I am doing a basic chemistry paper by correspondance over the holidays from my university.
I am unsure if I am going in the right direction for basic redox.
I can understand redox equations of the following form, I break these down into half equations and combine them.
$MnO_4^- + C_2O_4^{2-} => Mn^{2+} + CO_... |
I am doing a basic chemistry paper by correspondance over the holidays from my university.
I am unsure if I am going in the right direction for basic redox.
I can understand redox equations of the following form, I break these down into half equations and combine them.
$$\ce{MnO_4^- + C_2O_4^{2-} -> Mn^{2+} + ... |
I think your transition, if present, may be drowned out by noise, as your RDF is only produced by 108 particles. As the Lennard-Jones interaction is quite simple and you are using cutoffs (good idea!), is it possible to increase the number of particles in your simulation somewhat, or else take the mean of some large nu... |
Can someone please explain what photodissociation is and if it is more efficient than electrolysis while splitting water into its components?
Thanks in advance. |
What makes Coke and other soft drinks acidic? These drinks are carbonated, so a freshly-opened can should have a lot of dissolved carbonic acid, but the ingredients also lists phosphoric acid. Would flat Coke be significantly less acidic than carbonated Coke? |
What makes Coke acidic? |
So, a simple question: what makes neon a gas; what makes water liquid; what makes plutonium-238 a solid at room temperature? Of course, the phase is determined by the excitation of the molecules, but what determines that excitation? |
What defines matter's phase at room temperature? |
It's all in the intermolecular forces (and the air pressure). Intermolecular forces are the forces of attraction and repulsion between molecules to neighboring particles. To understand how they determine physical properties like enthalpies of vaporization, fusion, etc..., you need to think about what states of matter a... |
It's all in the intermolecular forces (and the air pressure). Intermolecular forces are the forces of attraction and repulsion between molecules to neighboring particles. To understand how they determine physical properties like enthalpies of vaporization, fusion, etc..., you need to think about what states of matter a... |
It's all in the intermolecular forces (and the air pressure). Intermolecular forces are the forces of attraction and repulsion between molecules to neighboring particles. To understand how they determine physical properties like enthalpies of vaporization, fusion, etc..., you need to think about what states of matter a... |
It's all in the intermolecular forces (and the air pressure). Intermolecular forces are the forces of attraction and repulsion between molecules to neighboring particles. To understand how they determine physical properties like enthalpies of vaporization, fusion, etc..., you need to think about what states of matter a... |
Anhydrous magnesium chloride will absorb ammonia to the tune of ($\ce{Mg(NH3)6Cl2}$).
Incidentally, magnesium chloride is usually a hexahydrate ($\ce{MgCl2(H2O)6}$) at STP.
My question is, could magnesium chloride be induced to absorb both ammonia and water at the same time? Since both of the absorbed molecules ... |
Can magnesium chloride absorb water and ammonia at the same time? |
Background:
I was a chemistry major and have recently started watching the awesome series of videos by NurdRage. Totally rekindled my interest in chemistry.
I learned that platinum dissolves in aqua regia but ruthenium is only attacked by high temperature halogens and some alkalis.
Question:
Would a ruthenium ... |
Completely chemically inert metal alloy? |
###Background:
I was a chemistry major and have recently started watching this series of videos by [NurdRage][1].
I learned that [Platinum dissolves in Aqua Regia][2] but [Ruthenium is only attacked by high temperature halogens and some alkalis][3].
###Question:
Would a Ruthenium and Platinum alloy be resist... |
I found as I was preparing to teach "Introduction to thermodynamics" that there are varying definitions or examples of pure substances. For instance the text book I have to use **"Thermodynamics an engineering approach, Cengel and Boles"** defines a pure substance as one that has the same chemical composition throughou... |
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