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Why is the orbital angular momentum of a pi electron along the axis of two atoms' molecule one? |
Is there a relation between the ionization energy and the electron affinity? |
In fact $Cu$ don't release electron, only $Zn$ does. For the usual explanation see [this wikipedia article](http://en.wikipedia.org/wiki/Lemon_battery), I will try to explain it in other words to make it much easier.
----------
One important thing that you should know is that energy comes from metal not from ... |
So I suspect that you would have both these molecular equations:
$\ce{2KCl(aq) + Na2SO4(aq) -> K2SO4(aq) + 2NaCl(aq)}$
$\ce{Ca(NO3)2(aq) + Na2SO4(aq) -> 2NaNO3(aq) + CaSO4(aq)}$
To answer your question with "What is a complete reaction?":
>"A complete reaction is one where all of at least one of the availab... |
In Germanium, if two electrons go from 1s go to 4p is it in its excited state? |
If two electrons move up to a higher energy level in an atom, is it considered excited? |
The universe cooled after the Big Bang. There was certainly an epoch when the universe's overall temperature decreased from 200°C to -40°C throughout a *very* large volume. There is your test tube (more like a Florence flask) for abiogenesis and then the panspermia reservoir.
Before you suspect the preceding is cl... |
Okay, here's what I did (and I highly encourage everybody to do this along with this tutorial-style answer, just so you get the feel for prepping and looking at data from the world wild web).
Data Acquisition
----
First, I went and copied the data from the tables at Wikipedia: [This one][1] for the ionization ener... |
Calculate the wavelength of the radiation released when an electron moves from n= 5 to n=2.
I thought this question was easy. But I did it 5 times and I get the wrong answer every time. I don't know. I think it is a careless mistake. But. Can someone give me the answer and explain it so I know where did I mess up??
... |
Calculate the wavelength of the radiation released when an electron moves from n= 5 to n=2.
I thought this question was easy. But I did it 5 times and I get the wrong answer every time. I don't know. I think it is a careless mistake. But. Can someone give me the answer and explain it so I know where did I mess up??
... |
I am getting confused between the type of mesomeric effect (+M or -M) shown by compounds containing $\ce-COX$ where $\ce X$ is an electronegative element.
Examples: $\ce -CONHCH_3$, $\ce -COOCH_3$, $\ce -COOH$. According to me, all these compounds must show both +M as well as -M effect. Since the group (e.g. $\ce -... |
I am getting confused between the type of mesomeric effect (+M or -M) shown by compounds containing $\ce{-COX}$ where $\ce{X}$ is an electronegative element.
Examples: $\ce{-CONHCH3}$, $\ce{-COOCH3}$, $\ce{-COOH}$.
According to me, all these compounds must show both a +M as well as a -M effect. Since the group (... |
Okay, here's what I did (and I highly encourage everybody to do this along with this tutorial-style answer, just so you get the feel for prepping and looking at data from the world wild web).
Data Acquisition
----
First, I went and copied the data from the tables at Wikipedia: [This one][1] for the ionization ener... |
Let's have a look at some fundamental data and the chemistry involved.
1. Chlorine is an inflammable gas with a boiling point of -35 °C and a nice yellowish-green colour. It is heavier than air.
- It is highly irritant and toxic. It is a strong oxidant. With water, it partly decomposes to hydrogen chloride and hyp... |
Let's have a look at some fundamental data and the chemistry involved.
1. Chlorine is an inflammable gas with a boiling point of -35 °C and a nice yellowish-green colour. It is heavier than air.
- It is highly irritant and toxic. It is a strong oxidant. With water, it partly decomposes to hydrogen chloride and hyp... |
$\ce{H2C=C=O}$ what is the group of the molecule? How to characterize it and how is this dissimilar to ketone?
If we add $\ce{O2}$ with it then will we get $\ce{CO2}$? |
We had analytical chemistry experiments to determine acidic radicals from a mixture of two salts. After the chloroform-chlorine water test for distinction between halides $(\ce{salt\ solution + H2SO4 + CHCl3 + Cl2_{(aq)}})$ when I emptied the test-tube in the sink, all of it suddenly turned yellow.
What reaction cou... |
Yellow precipitate in the presence of ammonium molybdate? |
I'm reading quantum chemistry. The book says that the orbital angular momentum of a $\pi$ electron along the symmetry axis of a molecule made up of two atoms is $\pm 1$. I think this is a primary question, but I do not konw why(I'm a student studying physics). In these days, I have a preliminary understanding of this:<... |
I'm reading quantum chemistry. The book says that the orbital angular momentum of a $\pi$ electron along the symmetry axis of a molecule made up of two atoms is $\pm 1$. I think this is a primary question, but I do not konw why(I'm a student studying physics).
<hr/>In these days, I have a preliminary understanding of... |
Let's start straight away. In [this](http://books.google.co.in/books?id=32RJvfgkJgwC&q=GaAs#v=snippet&q=GaAs&f=false) book on page 4 Gallium arsenide's bond structure is shown like this:
$As$ is shown making $5$ covalent bonds.
Recently I came across [this](http://bo... |
Let's start straight away. In [this](http://books.google.co.in/books?id=32RJvfgkJgwC&q=GaAs#v=snippet&q=GaAs&f=false) book on page 4 Gallium arsenide's bond structure is shown like this:
$As$ is shown making $5$ covalent bonds.
Recently I came across [this](http://bo... |
I'm reading quantum chemistry. The book says that the orbital angular momentum of a $\pi$ electron along the symmetry axis of a molecule made up of two atoms is $\pm 1$. I think this is a primary question, but I do not konw why(I'm a student studying physics).
<hr/>I currently have a preliminary understanding of this... |
Oxidize to the dialdehyde (Jones reagent), decarbonylate with rhodium (do it at the bench before building the pilot plant), reduce the CO to methanol. Why would you want to do that?
|
I want to produce alginate nanoparticles from NaAlg. I choosed nebulizing NaAlg solution into CaCl2 solution but 2% (m/v) NaAlg solution is quite viscous. What should I do to make it inviscid? |
Dilute the feed solution tenfold, etc. Inelegant. Try solution engineering,
http://www1.lsbu.ac.uk/water/kosmos.html <BR>
Chaotropes and kosmotropes.
http://en.wikipedia.org/wiki/Theta_solvent <BR>
Add a little "poor" solvent like ethanol or acetone to ball the polymer, disrupting hydrogen bond crosslinking ... |
The problem can be solved using **retrosythesis**.
You look at the product and imagine how that was made.
It's like looking at Lego construction, trying to identify the pieces - or looking at a pair of jeans, trying to identify how it was stitched together.
Then you go back and do the same for the previous bui... |
The problem can be solved using **retrosythesis**.
You look at the product and imagine how that was made.
It's like looking at Lego construction, trying to identify the pieces - or looking at a pair of jeans, trying to identify how it was stitched together.
Then you go back and do the same for the previous bui... |
I want to produce alginate nanoparticles from NaAlg. I choosed nebulizing NaAlg solution into $\ce{CaCl2}$ solution but 2% (m/v) NaAlg solution is quite viscous. What should I do to make it inviscid? |
I've been using QuteMol for generating 3D animated molecular images and I've encountered a problem; for some reason that's a complete mystery to me when I create a pdb file for etravirine (using MarvinSketch to create a sdf file and then using OpenBabel to convert the sdf to pdb and add implicit hydrogens) and load it ... |
Well, we know that charge is <a href="http://en.wikipedia.org/wiki/Elementary_charge#Quantization">quantized</a>. Quoting wikipedia below,
>Charge quantization is the principle that the charge of any object is an integer multiple of the elementary charge.
And we know that there is <a href="http://en.wikipedia.org... |
Does partial charge violate the law of quantization of charge? |
When a room is not ventilated for a long time (days if people are present, weeks if not), humans perceive a change in air quality commonly described as "stale" or "stuffy" air.
**What is going on here chemically? How is "stale" air different from normal air?**
Note that the difference cannot be the mere presence ... |
What is "stuffy"/"stale" air composed of? |
Safety concerns for radical halogenations of methane in sunlight? |
Among my friends it is a sort of 'common wisdom' that you should throw away water after a couple of days if it was taken from the tap and stored in a bottle outside the fridge, because it has 'gone bad'.
First of all, the couple of days is not very well defined, which already makes me a bit suspicious. Second, I canno... |
Does water really 'go bad' after a couple of days? |
Apologies if this is in the wrong section first of all.
The answer is likely very obvious but I know pretty much nothing about this so:
Can I make an alloy, using an alloy? That is, could I make an alloy of steel (in itself an alloy of iron and carbon) and silver? |
can an alloy be used to make another alloy? |
The answer is likely very obvious but I know pretty much nothing about this so:
Can I make an alloy, using an alloy? That is, could I make an alloy of steel (in itself an alloy of iron and carbon) and silver? |
why HClO4 is more acidic than HBrO4? But HCl is less acidic than HBr.
what determine the acidity? concentration of H+? So how this trends developed along the halogen group. |
I have to do an experiment where I will find out what the influence of the concentration on the reactionspeed of a homogenous reaction is.
We are asked to create 2 solutions, respectively A and B:
$\ce{KI + Na2S2O3 + Starch}$ (+water)
and
$\ce{H2O2 + H2SO4}$ (+water)
As long as A and B aren't added ... |
I am not an expert and its been a long time since I last studied chem and bio. The best answer will probably only come from a biologist. But out of interest, I will try to answer. Also, I suggest that you post this question on websites such as http://www.askabiologist.org.uk/ . Its likely that you will get some
good ... |
I was wondering what happens when you boil dry a solution of several salts for example a solution of KCl and NaNO3. Since the ions dissociate I was wondering if the ions would combine randomly upon being boiled out of solution making the original salts as well as KNO3 and NaCl? Does this happen? If not why?
Also in a ... |
First, I would like to say that I understand the basic idea of disassociation and solubility. However, as I study intermolecular forces I feel like this basic Idea is being challenged. My understanding from basic chemistry is that ionic bonds are much stronger than covalent bonds, due to the actual exchange of electron... |
Assuming you are talking about acids in water, and taking into account that the acids you mention are all regarded as *strong* acids, I would focus on the relative stability of the corresponding conjugated bases.
$\ce{Br-}$ being larger than $\ce{Cl-}$ can better allocate the negative charge. Then, $\ce{HBr}$ ($pK_{... |
I'm using a sensor that measures CO2 in ppm by volume aka atmosphere.
What I'm using it for is to measure CO2 concentration in water which is measured in ppm by weight.
This is what I have so far
Ppmwco2 = ppmvco2 * 0.8317 * 44.01 / 10000;
// quicker than co2/1000000 * 0.8317 * 44.01 / 1000000
... |
Convert co2 ppm volume to ppm weight? |
Why is $\ce{HClO4}$ more acidic than $\ce{HBrO4}$? But $\ce{HCl}$ is less acidic than $\ce{HBr}$? What determines the acidity? Is it the concentration of $\ce{H+}$? If so, how do these trends develop along the halogen group? |
[Here][1] is an explanation for alpha- and beta- glucose.
What it doesn't say is that the alpha-glucose can convert to beta-glucose and back again. Once the linkage is formed, it cannot change from alpha to beta.
Alpha linkage has the oxygen (on the aldehyde or ketone) below the ring and the beta has it above the r... |
I'm a
>I've also read online that adding $\ce{H2O2}$ and $\ce{H2SO4}$ creates a "Piranha" solution [...]
This is true - in principle. In reality, [*Piranha solution*][2] is made from **concentrated** sulfuric acid and **30%** hydrogen peroxide.
In the case of your experminent, you will most likely use diluted... |
As everyone knows, the atomic orbital can be classified as $s, p_z, p_x, p_y, d_{z^2},d_{xz},d_{yz},d_{xy},d_{x^2-y^2}$ and so on. I want to know the meaning of $z^2,x^2-y^2$ and so on. Maybe this is a fundamental question, but I'm not familiar with chemistry.
<HR/>
I have some ideas about this:
1. For example, w... |
What does the subscript of atomic orbital mean? |
It is quite well established that a stoichiometric Gallium-Arsenide (CAS 1303-00-0) compound forms a zincblende analogous structure. It consists of two stacked face-sentered cubic lattice systems ([Ioffe Physical Technical Institute database][1]). See also Uncle Al's Answer (the picture is misleading as Ga and As are r... |
I haven't used MarvinSketch in a while, but isn't it a 2D editor?
Generation of 3D coordinates from 2D files often means trouble. I tried that recently with a 2D BKChem drawing of a trypticene-based ligand for another answer and the result was useless.
I definitely recommend the use of **Avogadro** as a free 3D e... |
It is quite well established that a stoichiometric Gallium-Arsenide (CAS 1303-00-0) compound forms a zincblende analogous structure. It consists of two stacked face-centered cubic lattice systems ([Ioffe Physical Technical Institute database][1]). See also Uncle Al's Answer (the picture is misleading as Ga and As are r... |
I haven't used MarvinSketch in a while, but isn't it a 2D editor?
Generation of 3D coordinates from 2D files often means trouble. I tried that recently with a 2D BKChem drawing of a trypticene-based ligand for another answer and the result was useless.
I definitely recommend the use of **Avogadro** as a free 3D e... |
I am reading this [wikipedia article](http://en.wikipedia.org/wiki/Crisscross_method) that I don't understand. What I don't understand is:
>suppose we have two elements $X$ and $Y$ having oxidation numbers $x$ and $y$ respectively. Can we prove that the compound formed will be $X_yY_x$.
I tried to understand th... |
I haven't used MarvinSketch in a while, but isn't it a 2D editor?
Generation of 3D coordinates from 2D files often means trouble. I tried that recently with a 2D BKChem drawing of a trypticene-based ligand for another answer and the result was useless.
I definitely recommend the use of **Avogadro** as a free 3D e... |
##What is the logic behind this method, how to prove this method?
The logic of the method is in fact trivial. Suppose you have to write a compound knowing his oxidation numbers :
$$\ce{xA^{a} + yB^{b} -> A_{x}B_{y}}$$
Where $a$ and $b$ are **oxidation numbers** that have opposite sings, $A$, $B$ chemical speci... |
Why Gold and Silver does not react with atmosphere? |
##What is the logic behind this method, how to prove this method?
The logic of the method is in fact trivial. Suppose you have to write a compound knowing his oxidation numbers :
$$\ce{xA^{a} + yB^{b} -> A_{x}B_{y}}$$
Where $a$ and $b$ are **oxidation numbers** that have opposite sings, $A$, $B$ chemical speci... |
Why Gold and Silver react minimally with atmosphere? |
Copper, silver, gold. What is the energy of the highest "s" orbital versus the highest "d" orbital? Gold is a very heavy nucleus. An "s" orbital has non-zero probability at its nucleus. Special relativity effects make its "s" electrons more massive, bringing them into the atom.
A silver atom is a soft Lewis acid.... |
I haven't used MarvinSketch in a while, but isn't it a 2D editor?
Generation of 3D coordinates from 2D files often means trouble. I tried that recently with a 2D BKChem drawing of a trypticene-based ligand for another answer and the result was useless.
I definitely recommend the use of **Avogadro** as a free 3D e... |
Once made by heating wood in the absence of air, methanol (CH3OH) is now made by reacting carbon monoxide and hydrogen at high pressure:
CO(g)+2H2(g)→CH3OH(l)
How many grams of CH3OH can be made from 30.0g of CO if it all reacts? |
How many grams of CH3OH can be made from 30.0g of CO if it all reacts? |
Once made by heating wood in the absence of air, methanol ($\ce{CH3OH}$) is now made by reacting carbon monoxide and hydrogen at high pressure:
$\ce{CO_{(g)} + 2 H2_{(g)} -> CH3OH_{(l)}}$
How many grams of $\ce{CH3OH}$ can be made from 30.0g of $\ce{CO}$ if it all reacts? |
I am currently studying computational chemistry and I am trying to understand the UV-VIS absorption of molecules. I know that UV-VIS absorption is electronic excitation and requires a spesific energy.
What I don't understand is why a molecule can not absorb a shorter wavelength as it has more energy? A slightly hig... |
A molecule absorbs light having a spesific wavelength, why doesn't it absorb shorter wavelengths? |
Gold and Silver atoms interact with one another to form reasonably strong metallic bonds, but surprisingly they have almost no chemical interaction with atmosphere. How can we explain it based on the atomic structure of Gold and Silver. What is so unique about its chemical structure that is not present in other transit... |
What is the correct structure for the NO2 compound (not ion)? I always thought it was like:
![enter image description here][1]
since the negative charge would be residing the on the highly electronegative oxygen, but was reading this [blogpost][2] by the guys at WolframAlpha who state that contrary to popular b... |
Structure of NO2 compound? |
Given these standard reduction potentials, what is the standard reduction potential for
Co3+(aq) +3e- :rarrow: Co(s)
____________________________________________________________________
Given:
Co3+(aq) + e- :rarrow: Co2+(aq) E°=1.82V
Co2+(aq) + 2e- :rarrow: Co(s) E°=-0.28 V
____________________... |
I am given a protein, BAPNA, and the initial concentration of the protein. The experiment involves reaction rates of varying protein concentrations. Each sample cuvette is inserted into a spectrometer, 100% Transmittance is set, has the enzyme inserted, and then has transmittance measured every 20s for 600s.
I under... |
Maybe OP has already contacted the authors of this paper by now, but this was interesting. I'm no expert but I can Google things and this was too long for a comment.
**Antisymmetric exchange:**
At first I thought it was simply an [exchange interaction] where the wave function's sign is changed during exchange, now ... |
Given these standard reduction potentials, what is the standard reduction potential for
$$
\ce{Co^{3+}(aq) +3e- -> Co(s)}
$$
Given:
$$
\ce{Co3+(aq) + e- -> Co2+(aq) \ \ \ E°=1.82V}
$$
$$
\ce{Co2+(aq) + 2e- -> Co(s) \ \ \ E°=-0.28 V}
$$
When you add them up to get the net equation, you get ... |
I am currently studying computational chemistry and I am trying to understand the UV-VIS absorption of molecules. I know that UV-VIS absorption is electronic excitation and requires a specific energy.
What I don't understand is why a molecule can not absorb a shorter wavelength as it has more energy? A slightly hig... |
A molecule absorbs light having a specific wavelength, why doesn't it absorb shorter wavelengths? |
Why only two atoms share an electron and not three? |
> The only given concentration is the initial concentration [...]
Unless there is a major misunderstanding on my side, you have all the data you need.
**Given** the initial concentration $c_0$ and **knowing** the path length $d$ of your cuvette, you **measure** the extinktion $E$ at this point and use - as you ha... |
Given these standard reduction potentials, what is the standard reduction potential for
$$
\ce{Co^{3+}(aq) +3e- -> Co(s)}
$$
Given:
$$
\ce{Co3+(aq) + e- -> Co2+(aq)} \ \ \ E°=1.82 V
$$
$$
\ce{Co2+(aq) + 2e- -> Co(s)} \ \ \ E°=-0.28 V
$$
When you add them up to get the net equation, you get... |
Example of raw 1H-NMR data? |
Given these standard reduction potentials, what is the standard reduction potential for
$$
\ce{Co^{3+}(aq) +3e- -> Co(s)}
$$
Given:
$$
\ce{Co^{3+}(aq) + e- -> Co^{2+}(aq)} \ \ \ E°=1.82 V
$$
$$
\ce{Co^{2+}(aq) + 2e- -> Co(s)} \ \ \ E°=-0.28 V
$$
When you add them up to get the net equation... |
> The only given concentration is the initial concentration [...]
Unless there is a major misunderstanding on my side, you have all the data you need.
**Given** the initial concentration $c_0$ and **knowing** the path length $d$ of your cuvette, you **measure** the extinction $E$ at this point and use - as you ha... |
Why is it necessary to avoid even traces of moisture from a Grignard reagent? |
My book says the "angular momentum is always conserved in a transition". But if suppose we have a s electron then it's angular momentum is $\hbar\sqrt{l(l+1)}+\hbar\sqrt{s(s+1)}$ $\implies \hbar\frac{\sqrt{3}}{2}$ and suppose it transits to a p electron (which is in accordance with the selection rule as $\Delta l=1$) w... |
what purpose do chain reactions serve? |
What purpose do chain reactions serve? |
I think you have misunderstood some concept. The angular momentum of spin is just $\sqrt{s(s+1)}\hbar$. The spin which we always say is spin projection quantum number in fact not the angular momentum. And I'm not familiar with chemistry, but I know that we can not add up the orbital and spin angular momentum directly b... |
Nuclear reactors and warheads, addition polymers (all hail Parylenes, too, and linear low density polyethylene, epoxy resins, truck liner beds, synthetic rubbers), genomes into proteomes, fire...to "gray goo." Now, some footnotes.
http://en.wikipedia.org/wiki/Living_polymerization
CONTROL. A free radical polyme... |
#A practical tutorial with [Avogadro](http://avogadro.cc/wiki/Main_Page)
![enter image description here][1]
Is not so easy to understand from the structure because polarity in fact depends from the arrangement of the groups in the tridimensional space not only from the groups it self (e.g. $\ce{trans-C2H2Cl2}$ is n... |
This is a very simple and short question. I am looking for liquids that are low/non-volatile at 20$^\circ$C (at least substantially less volatile than water) which have a high contact angle with glass and oxidized silicon (in air) or with a coating of perfluoroalkanes (specifically [Perfluorodecyltrichlorosilane][1]). ... |
Here it comes... mercury. 75-wt% Ga 25 wti%, mp. 15.5 C and
http://en.wikipedia.org/wiki/Galinstan
in general wet glass. Maybe ionic liquids,
J. Am. Chem. Soc. 129(13), 3804 (2007), DOI: 10.1021/ja070169d <BR>
Aust. J. Chem. 57(2) 113-155 (2004)
http://www.researchgate.net/publication/233906460_Wetting_... |
I will be doing a lab on Hydrogen Phosphate buffer system tomorrow and I have a few questions about the buffer system. I am not sure if my assumptions are correct.
(1) What would happen to the rate of pH change if 5.0M HCl and NaOH were used instead of 0.50M?
My assumption is that, since the pH of the buffer does... |
http://www.ehs.neu.edu/hazardous_waste/fact_sheets/sodium_azide/
"Sodium azide reacts with heavy metals (such as silver, gold, lead, copper, brass, or solder in plumbing systems); and metal salts to form an accumulation of the highly explosive compounds such as lead azide and copper azide."
Assume reaction is fas... |
I'm a student in highschool AP chemistry.
I'm confused about a certain problem in my chem textbook. In summary, I am given a species and asked to identify its basicity as strong, weak, or negligible. I must then give its conjugate acid and identify likewise for its acidity. (in the context of Bronsted-Lowry theory)
... |
#A practical tutorial with [Avogadro](http://avogadro.cc/wiki/Main_Page)
![enter image description here][1]
It is not so easy to understand from the structure because polarity in fact depends on the arrangement of the groups in tridimensional space relative to one another and not simply on the groups present (e.g. ... |
If I have a cup of milk and a cup of tea; to get them to a sweetness I like, I usually add less sugar to the milk as compared to the tea.
Why is it that milk needs less sugar to be just as sweet as tea?
P.S. I'm not sure if this is the right SE site to post this que, but I can't find another more suitable. |
Why does sweetening milk need less sugar as compared to tea? |
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