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How can sodium be reduced in the Castner–Kellner process? |
Im going to analyse plasma samples that contain a lot of fibrin. It is necessary to centrifuge the samples to be able to pipett the plasma. After the samples are centrifuged I cant vortex them because then I mix everything again and it wont be possible to pipett. Now I wonder if it is necessary to vortex them before I ... |
Is it necessary to vortex before centrifugation? |
I read chapter 9 in the book Biochemistry (5th edition), by Berg, Tymoczko, and Stryer (provided in the NCBI site [here](https://www.ncbi.nlm.nih.gov/books/NBK22526/)). It describes the mechanism of action of the chymotrypsin enzyme. The catalysis is performed through the catalytic triad consisting of serine-195, histi... |
How can subtilisin still function without its catalytic triad? |
I have been reading about the relation of molecular graph spectrum, that is, the set of eigenvalues of the Laplacian matrix of the molecular graph, and molecular properties. Recently, I came across a paper that finds an upper bond for maximum eigenvalue. To motivate their research, authors state that
> The eigenvalu... |
What is maximum energy level of molecules? |
I'm going to analyse plasma samples that contain a lot of fibrin. It is necessary to centrifuge the samples to be able to pipette the plasma. After the samples are centrifuged I can't vortex them because then I mix everything again and it wont be possible to pipette. Now I wonder whether it is necessary to vortex them ... |
To get plasma out of a blood sample, is it necessary to vortex sample before centrifugation? |
I have been reading about the relation of molecular graph spectrum, that is, the set of eigenvalues of the Laplacian matrix of the molecular graph, and molecular properties. Recently, I came across a paper that finds an upper bond for maximum eigenvalue (DOI: [10.1109/ICNC.2012.6234727](https://doi.org/10.1109/ICNC.201... |
> A 299 mL solution containing 21 g of a protein in toluene had an osmotic pressure of 0.053 atm at 27 degrees Celsius. What is the molar mass (in g/mol) of the protein?
We can use the formula that
$$\Pi = iMRT$$
where $\Pi$ is the osmotic pressure, $i$ the van't Hoff factor, $M$ being the molarity, $R$ being ... |
>Question: Consider the following reaction at equilibrium at a total pressure that we will call $P_1$.
>$$\ce{2 SO2(g) + O2(g) <=> 2 SO3(g)}$$
>Suppose the volume of the system is compressed to $\frac 12$ its initial volume and then equilibrium is reestablished. The new equilibrium total pressure will be:
>... |
In 1930, Palmer and Kipping<sup>[1][1]</sup> reported the formation of cyclohexyl magnesium bromide in ether in 50-60% yield. Although they did not make an effort to detect the coupling product, "bicyclohexyl" [choice (b)] in the Grignard reagent itself. Subsequent reaction of the Grignard reagent with SiCl<sub>4</sub>... |
In 1930, Palmer and Kipping<sup>[1][1]</sup> reported the formation of cyclohexyl magnesium bromide in ether in 50-60% yield. Although they did not make an effort to detect the coupling product, "bicyclohexyl" [choice (b)] in the Grignard reagent itself. Subsequent reaction of the Grignard reagent with SiCl<sub>4</sub>... |
In 1930, Palmer and Kipping<sup>[1][1]</sup> reported the formation of cyclohexyl magnesium bromide in ether in 50-60% yield. They did not make an effort to detect the coupling product, "bicyclohexyl" [choice (b)] in the Grignard reagent itself. Subsequent reaction of the Grignard reagent with SiCl<sub>4</sub> led to t... |
To get clear plasma out of a minute particle (such as fibrin), is it necessary to vortex sample before centrifugation? |
Can you create different colors of rust on iron? |
How can you explain the solubility of BeF2? |
In 1930, Palmer and Kipping<sup>[1][1]</sup> reported the formation of cyclohexyl magnesium bromide in ether in 50-60% yield. They did not make an effort to detect the coupling product, "bicyclohexyl" [choice (b)] in the Grignard reagent itself. Subsequent reaction of the Grignard reagent with SiCl<sub>4</sub> led to t... |
**The entropy of the system decreases**
All the reactants are mono-atomic gases, and the product is a solid. This is a strong indication that the entropy of the system decreases.
**The reaction is spontaneous**
That statement from the text of the question means that the Gibbs energy of reaction is negative. It... |
The following articles suggest that the data reported from Solomons, Fryhle and Snyder Organic Chemistry is likely **incorrect.**
- Maya Paabo, Roger G. Bates and R. A. Robinson ("[Dissociation of Acetic Acid-d3 in Aqueous Solution and Related Isotope Effects from 0 to 50°](https://doi.org/10.1021/j100874a037)", J.... |
> A 299 mL solution containing 21 g of a protein in toluene had an osmotic pressure of 0.053 atm at 27 degrees Celsius. What is the molar mass (in g/mol) of the protein?
We can use the formula that
$$\Pi = iMRT$$
where $\Pi$ is the osmotic pressure, $i$ the van't Hoff factor, $M$ being the molarity, $R$ being ... |
Why is $\ce{H_2SO_4}$ more acidic than $\ce{HNO_3}$. Shouldn't it be the other way around because $\ce{N}$ is more electronegative than $\ce{O}$?
My reason: $\ce{O}$ can take electrons more easily from $\ce{S}$ than from $\ce{N}$. Hence, it will be more difficult to remove $\ce{H}$ from $\ce{H2SO4}$ than from $\ce{... |
Why is $\ce{H_2SO_4}$ more acidic than $\ce{HNO_3}$. Shouldn't it be the other way around because $\ce{N}$ is more electronegative than $\ce{S}$?
My reason: $\ce{O}$ can take electrons more easily from $\ce{S}$ than from $\ce{N}$. Hence, it will be more difficult to remove $\ce{H}$ from $\ce{H2SO4}$ than from $\ce{... |
Say you have a hydrogen atom then would the proton of the atom and the electron of the atom ,in some way, have some criteria to be uniquely associated with each other?
This confusion for me occurs when I hear about ionization, the process of removing an electron from an atom, if you ionize an atom then it loses its ... |
Does each proton have a uniquely associated electron? |
Zn which has the highest ionisation enthalpy in 3d series.The reason given in my textbook is:
>The value of zinc is higher because it represent ionisation from 4s level.
This is not correct because for every 3d element ionisation is from 4s orbital. The explanation I found for this is from this site is:
https:... |
**The entropy of the system decreases**
All the reactants are mono-atomic gases, and the product is a solid. This is a strong indication that the entropy of the system decreases.
**The reaction is spontaneous**
That statement from the text of the question means that the Gibbs energy of reaction is negative. It... |
Sn(no3)2 when subjected to strong heat then what are the products formed?
I searched over the internet but I didn't get any satisfactory answer.
Please help me out. |
**The entropy of the system decreases**
All the reactants are mono-atomic gases, and the product is a solid. This is a strong indication that the entropy of the system decreases.
**The reaction is spontaneous**
That statement from the text of the question means that the Gibbs energy of reaction is negative. It... |
What is the melecularity of a reaction if it has a fractional order as per rate equation? |
Smaller particles in a colloidal dispersion are less stable than larger ones due to their higher surface to volume ratio.
Therefore Ostwald ripening occurs, a process which promotes growth of larger particles at the expense of smaller ones (alternatively aggregation of smaller particles can occur).
In principle, ... |
Why are colloidal dispersions stable? |
What are the products formed when $\ce{Sn(NO3)2}$ is subjected to high temperatures?
I searched over the internet but I didn't get any satisfactory answer.
|
>[OP] Would this last electron, in any way, be related to the original atom and would the original atom 'want' to regain it's lost electron?
No. Individual electrons are indistinguishable. The experimental evidence goes along these lines (source: https://medium.com/physics-as-a-foreign-language/how-do-we-know-that-a... |
Say you have a hydrogen atom. Would the proton of the atom and the electron of the atom, in some way, have some criteria to be uniquely associated with each other?
This confusion for me occurs when I hear about ionization, the process of removing an electron from an atom. If you ionize an atom then it loses its elec... |
For example, this reaction, is a dehydration reaction
$\ce{ HNO3+ P4O10 -> N2O5 + HPO3} $
If I were only given the reactants side of the equation, how would I predict the products side of it?
What I have seen already:
https://chemistry.stackexchange.com/questions/50684/how-can-i-predict-if-a-reaction-will-occ... |
Wouldn't CO2 be IR inactive because of its non-polar bonds? |
Why sigma bond has C2 symmetry not C∞? |
In (I think all) of the molecular orbitals (MO) diagrams I have seen, I have observed that the number of antibonding molecules is the same as the number of bonding molecular orbitals.
Here are some for example:
[![enter image description here][1]][1]
[![enter image description here][2]][2]
I know that the nu... |
What is the molecularity of a reaction if it has a fractional order as per rate equation? |
today I was asked to show that the perpendicular height, H, of a regular tetrahedron is related to the length of a side, L, of the tetrahedron, by H = (2/3) x L. I did this no problem.
I was then asked:
Explain how this is relevant in determining a relationship between the unit cell parameters, a and c, of a hexag... |
HCP unit cell (help!?) |
Optical activity gets complicated quickly and the following question is intended to avoid threshold confusion. The linked [lecture note][1]* seems very accessible to me and Table 10.6 in particular is quite clear. On page 2 the author writes, "Optical rotation results from circular birefringence..." and then relates th... |
What is the difference between quantities reported as optical rotation and circular birefringence? |
I'm having trouble finding a posted literature value for the activation energy for the Daniell Cell redox reaction:
Cu2+ + Zn -> Cu + Zn2+
Where might I be able to find this information?
Thanks |
What is the activation energy of a Daniell Cell? |
What are the parameters which govern the current density in an electrowinning cell? What equations relate Current Density to the applied potential difference?
Is it simply just Ohm’s Law J = σE? Where does redox at the electrodes come into play, if this is the case?
|
A picture is worth a thousand words (see the two tetrahedra heights making up the vertical c-axis?):
[![enter image description here][1]][1]
The HCP packing has layers of closest-packed spheres in an ABAB... pattern. The distance between layers is one height of a tetrahedron, and you need two layers to get a repe... |
today I was asked to show that the perpendicular height, H, of a regular tetrahedron is related to the length of a side, L, of the tetrahedron, by $H = \sqrt{(2/3)} \cdot L$. I did this no problem.
I was then asked:
Explain how this is relevant in determining a relationship between the unit cell parameters, a and c... |
Today I was asked to show that the perpendicular height, H, of a regular tetrahedron is related to the length of a side, L, of the tetrahedron, by $H = \sqrt{(2/3)} \cdot L$. I did this no problem.
I was then asked:
Explain how this is relevant in determining a relationship between the unit cell parameters, a and c... |
No, it is not the case that all exothermic reactions are spontaneous. More generally, it doesn't even make sense to make a broad statement that a reaction is or is not spontaneous without also specifying the concentrations of reactants and products, since for a certain relative concentration of reactants and products,... |
No, it is not the case that all exothermic reactions are spontaneous. More generally, it doesn't even make sense to make a broad statement that a reaction is or is not spontaneous without also specifying the concentrations of reactants and products, since for a certain relative concentration of reactants and products,... |
I am currently studying the textbook *Infrared and Raman Spectroscopy* by Larkin. In the first chapter of the textbook, the author (probably prematurely) opens with the following statement:
> Near-IR spectroscopy measures the broad overtone and combination bands of some of the fundamental vibrations (only the higher... |
I am currently studying the textbook *Infrared and Raman Spectroscopy* by Larkin. In the first chapter of the textbook, the author opens (probably prematurely) with the following statement:
> Near-IR spectroscopy measures the broad overtone and combination bands of some of the fundamental vibrations (only the higher... |
My interest is primarily food-related here but I think this is a fairly general chemistry question. Let's say I took some liquid like lemon juice and ran it though a rotary evaporator to get just the volatile compounds. In the case of lemon juice I'd assume I'd wind up with mostly water, and some other volatile compoun... |
With reference to coordination compounds, most chelate rings formed with the metal atom and ligands are 5-member rings (including the central metal atom), such as complexes with Oxalate, ethylenediamine, dimethylglyoxime and glycinate ions as complexing agents.
**Are there any compounds which contain stable 4-member... |
are there any stable four membered chelate rings? |
How to set up an equation to solve a rate law computationally? |
Considering a wide variety of chromatographic columns used for [(U)HPLC](https://en.wikipedia.org/wiki/High-performance_liquid_chromatography) based on
- phase type (normal/reverse);
- column dimensions (geometry/length/inner diameter);
- particle size, shape and porosity;
- dopants/modifiers etc.,
as well as ... |
Is there a list of must-have columns for LC-MS/MS used in biochemistry/clinical lab setting? |
Today I was asked to show that the perpendicular height, H, of a regular tetrahedron is related to the length of a side, L, of the tetrahedron, by $H = \sqrt{(2/3)} \cdot L$. I did this no problem.
I was then asked:
Explain how this is relevant in determining a relationship between the unit cell parameters, a and c... |
When comparing maximum reactivity of a compound in electrophillic addition, what factors are kept in mind while comparing propene and trans-2-butene?
Why use trans-2-butene more reactive in this case than propene? |
Today I was asked to show that the perpendicular height, $H,$ of a regular tetrahedron is related to the length of a side, $L,$ of the tetrahedron, by $H = \sqrt{(2/3)} \cdot L$. I did this no problem.
I was then asked:
Explain how this is relevant in determining a relationship between the unit cell parameters, $a$... |
Say you have a hydrogen atom. Would the proton of the atom and the electron of the atom, in some way, have some criteria to be uniquely associated with each other?
This confusion for me occurs when I hear about ionization, the process of removing an electron from an atom. If you ionize an atom then it loses its elec... |
I am parameterizing a force field and would need to obtain non-bonded interaction parameters of atoms (e.g., Lennard-Jones parameters).
My primary idea is to obtain a potential energy curve using the GAUSSIAN software and adjust the data on that curve to an equation that has non-bonded interaction parameters of atom... |
I am parameterizing a force field and would need to obtain non-bonded interaction parameters of atoms (e.g., Lennard-Jones parameters).
My primary idea is to obtain a potential energy curve using the Gaussian 09 software and adjust the data on that curve to an equation that has non-bonded interaction parameters of a... |
How to obtain curve energy and non-bonded interaction parameters (e.g. Lennard Jones parameters) with Gaussian? |
I am parameterizing a force field and would need to obtain non-bonded interaction parameters of atoms (e.g., Lennard-Jones parameters).
My primary idea is to obtain a potential energy curve using the Gaussian 09 software and fit the data on that curve to an equation that has non-bonded interaction parameters of atom... |
I am parameterizing a force field and would need to obtain non-bonded interaction parameters of atoms (e.g., Lennard-Jones parameters).
My primary idea is to obtain a potential energy curve using the Gaussian 09 software and fit the data on that curve to an equation that has non-bonded interaction parameters of atom... |
No, it is not the case that all exothermic reactions are spontaneous. More generally, it doesn't even make sense to make a broad statement that a reaction is or is not spontaneous without also specifying the concentrations of reactants and products, since for a certain relative concentration of reactants and products,... |
A typical empirical formula problem reads something like this:
> Determine the empirical formula for a compound that contains 35.98% aluminum and 64.02% sulfur. [source][1]
How would those percentages be determined in real life? Spectroscopy?
A percent composition problem would obviously yield percentages, but... |
Where do the percents in empirical formula questions come from? |
I am parameterizing a force field and would need to obtain non-bonded interaction parameters of atoms (e.g., Lennard-Jones parameters).
My primary idea is to obtain a potential energy curve using the Gaussian 09 software and fit the data on that curve to an equation that has non-bonded interaction parameters of atom... |
I am parameterizing a force field and would need to obtain non-bonded interaction parameters of atoms (e.g., Lennard-Jones parameters).
My primary idea is to obtain a potential energy curve using the Gaussian 09 software and fit the data on that curve to an equation that has non-bonded interaction parameters of atom... |
I am parameterizing a force field and would need to obtain non-bonded interaction parameters of atoms (e.g., Lennard-Jones parameters).
My primary idea is to obtain a potential energy curve using the Gaussian 09 software and fit the data on that curve to an equation that has non-bonded interaction parameters of atom... |
> How would those percentages be determined in real life? Spectroscopy?
You are right, this analysis comes in the domain of analytical chemistry. The fundamental requirement for formula determination is that your sample must be extremely pure.
There is a whole field. So there are two broad classes of approaches. ... |
If one consumes an amino acid chelate such as iron bisglycinate, it is generally absorbed intact as far as I am aware. At some point, presumably the iron could be used for say hemoglobin synthesis and the glycine for collagen synthesis. How exactly does the dissociation of this chelate occur in the body to support this... |
When and how do mineral chelates separate in the body? |
Because the burr ( grinding head ) is steel and maybe the bowl it fits into , why not leave the shaft as bare steel ? As long as the beans are dry there will be very little corrosion; maybe wipe the shaft with a paper towel once a week to prevent any coffee powder from building up on it. And you could wipe a little ve... |
One of the first things you tend to learn in organometallic chemistry is that transition metal compounds containing beta-hydrogens are unstable. There is a tendency for the beta hydrogen on the alkane to be abstracted by the metal leaving a metal hydride and a coordinated alkene, possibly followed by other reactions.
... |
Are there many examples of stable, well characterised organometallic compounds of saturated hydrocarbons with beta hydrogens? |
One of the first things you tend to learn in organometallic chemistry is that **transition metal** compounds containing beta-hydrogens are unstable (there are plenty of stable main groups ones; eg grignards seem pretty stable for most saturated aliphatics). There is a tendency for the beta hydrogen on the alkane to be ... |
To extract the force as in the title I used the gmx trjconv command like below.
gmx trjconv -f alad.trr -s alad.tpr -n alad.ndx -pbc mol -novel -force -o alad.gro
However, the force was not extracted in alad.gro file.
Of course I got the coordinates and the force at equal intervals when getting the alad.trr file... |
To extract the force as in the title I used the gmx trjconv command like below.
gmx trjconv -f alad.trr -s alad.tpr -n alad.ndx -pbc mol -novel -force -o alad.gro
However, the force was not extracted in alad.gro file.
Of course I got the coordinates and the force at equal intervals when getting the alad.trr file... |
If I understood correct, the high energy of atomisation for d-block element comes from the ability to make many metallic bonds due to half electron filled d-orbitals, but it seems here that copper has no free d-orbitals yet has high enthalpy of atomisation? Is there a mistake in my understanding or is there a reason fo... |
Why does copper have a high enthalpy of atomisation when it has a half filled d sub shell? |
Considering a wide variety of chromatographic columns used for [(U)HPLC](https://en.wikipedia.org/wiki/High-performance_liquid_chromatography) based on
- phase type (normal or reverse);
- column dimensions (geometry, length, inner diameter);
- particle material $(\ce{SiO2},$ $\ce{ZrO2},$ $\ce{TiO2},\ldots),$ size,... |
To extract the force as in the title I used the `gmx trjconv` command like below.
```
gmx trjconv -f alad.trr -s alad.tpr -n alad.ndx -pbc mol -novel -force -o alad.gro
```
However, the force was not extracted in `alad.gro` file.
Of course, I got the coordinates and the force at equal intervals when getting th... |
How to extract force when the center of mass of molecules is put in the box in GROMACS? |
Considering a wide variety of chromatographic columns used for [(U)HPLC](https://en.wikipedia.org/wiki/High-performance_liquid_chromatography) based on
- phase type (normal or reverse);
- column dimensions (geometry, length, inner diameter);
- particle material $(\ce{SiO2},$ $\ce{ZrO2},$ $\ce{TiO2},\ldots),$ size,... |
I was wondering is there nay test or way to find out how sweet is any drink? like if i mix sugar in water, how can i test its level or number of swettness?
|
Is there any way to chemically check sweetness level in any drink or water or tea etc? |
I'm having trouble finding a posted literature value for the activation energy for the Daniell cell redox reaction:
$$\ce{Cu^2+ + Zn -> Cu + Zn^2+}$$
Where might I be able to find this information? |
What is the activation energy of a Daniell cell? |
I understand that to separate molecules by HPLC (or SFC) you commonly adjust the pH of the mobile phase to get preferable charges (i.e. negative charges) on the molecules - so that they interact with the column and are therefore well separated and thus give a large distinct peak.
Im not completely sure I understand... |
Why are switter-ions difficult to detect by HPLC-MS alt. SFC-MS? |
I was wondering if there is a test or way to find out how sweet any drink is? For example, if I mix sugar in water, how can I test its level or number of sweetness?
|
> A $\pu{19.3 g}$ mixture of oxygen and argon is found to occupy a volume of $\pu{16.2 L}$ when measured at $\pu{675.9 mmHg}$ and $\pu{43.4 ^\circ{}C}$. What is the partial pressure of oxygen in this mixture?
The answer is $\pu{436 mmHg}$, but I didn't manage to get to it.
I know that it is found by the formula ... |
How to calculate the partial pressure of oxygen in this mixture of oxygen and argon? |
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