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Why is change in gibbs energy not zero through the gibbs free energy equation? |
I'm currently studying about the atomic configuration of electrostatic interactions. Concept is there that in case of interactions like in **N-H...N-H** (amides), the stability depends on the position of resonating electron between **H...N** nuclei ([THE NATURE OF THE CHEMICAL BOND. II. THE ONE-ELECTRON BOND AND THE TH... |
When I get the pressure using the different equations of state (e.g. van der Waals, Redlich-Kwong, etc.), will the answer still be the same? |
Why are salts of strongly electropositive element less heavily hydrated than the ones that are less electropositive? Shouldn't it be the other way round as the salts of electropositive elements are mostly ionic and hence strongly attracted by water molecules? |
Xenon tetroxide is tetrahedral despite having double bonds. Is it something to do with $d$ orbitals? Also things like sulfur trioxide (trigonal planar with three double bonds but the sulfur is hypervalent). Is it possible for the $\pi$ bond to be formed from overlap of $d$ orbitals from the central atom with $p$ orbita... |
What is Hybridization?
Spelling: Hybridisation (British English) / Hybridization (American English)
The hybridization is a concept that describes atomic orbitals. In other words: Hybridization is an approach to model hybrid orbitals mathematically.
The geometry of a molecule determines the hybridization and n... |
Is the hybridization only related to atomic orbitals but not to the molecular orbitals? |
What is Hybridization?
Spelling: Hybridisation (British English) / Hybridization (American English)
The hybridization is a concept that describes atomic orbitals. In other words: Hybridization is an approach to model hybrid orbitals mathematically.
The geometry of a molecule determines the hybridization and n... |
How can $\ce{CO2}$ be converted into Carbon and Oxygen?
$$\ce{CO2 -> C + O2}$$
Alternatively:
$$\ce{CO2 + ? -> C + O2}$$
I know that plants are able to do this. But I'm wondering if it can be done without using plants? |
A reaction of importance in the formation of smog is that between ozone and nitrogen monoxide described by
$\ce{O3(g) + NO(g)->O2(g) + NO2(g)}$
the rate law for this reaction is:
rate of reaction = $k\left[\ce{O3}\right]\left[\ce{NO}\right]$
Given that $k = 2.98 \times 10^6\ \mathrm{M^{–1}\cdot s^{–1}}$ at ... |
I'm currently studying about the atomic configuration of electrostatic interactions. Concept is there that in case of interactions like in **N-H...N-H** (amides), the stability depends on the position of resonating electron between **H...N** nuclei ([THE NATURE OF THE CHEMICAL BOND. II. THE ONE-ELECTRON BOND AND THE TH... |
I have the formula $\ce{Co(C2O4)*H2O}$ in a reaction that forms cobalt oxide $\ce{Co3O4}$ – My data here says that my oxalate hydrate weighed 0.3283 g and my product oxide weighed 0.1158 g which I have calculated as 0.1158 × (176.79 g cobalt / 240.79 g cobalt oxide) to equal 0.08502 g of cobalt in the original sample. ... |
Why are salts of strongly electropositive elements less heavily hydrated in aqueous solution than the those of less electropositive elements? Shouldn't it be the other way round as the salts of electropositive elements are mostly ionic and hence strongly attracted by water molecules? |
This seems like a farce...
http://www.nature.com/news/quantum-gas-goes-below-absolute-zero-1.12146
I have seen several recent articles like this one and I am extremely skeptical. Perhaps my skepticism is based upon an ignorance of physical principles, but I am less offended by apparent violations of the speed o... |
Even when ionic compounds are strong (e.g. rubies and sapphires), they are neither malleable nor ductile in the slightest, and if sufficient stress is put on them, they will shatter, not bend. Why is that? |
Why are so many ionic compounds brittle? |
What is Hybridization?
Spelling: Hybridisation (British English) / Hybridization (American English)
The hybridization is a concept that describes atomic orbitals. In other words: Hybridization is an approach to model hybrid orbitals mathematically.
The geometry of a molecule determines the hybridization and n... |
As the curve that represents the buffer capacity does not simply rely on one fraction of the whole system but on all species of the acid-base system it is not enough to only consider the derivative of $c(\ce{HA-})$.
You also have to take care of the other deprotonated species in your system. For the case of a diprot... |
The fundamental equation of thermodynamics, as us chemists (and chemical engineers!) are used to seeing it, is
$$ dG = - S~dT + V~dP + \sum_{i}\mu_i~dN_i$$
This gives the Gibbs free energy as a function of temperature, pressure, and composition, _assuming there are no other relevant forces other than mechanical ... |
If you have ever grown Aloe Vera and applied it to your skin, it feels a bit slimy. However, after it evaporates it has a cool feeling on your skin.
Also, why does the Aloe Vera evaporate so fast? What is it made of, apart from water that makes Aloe Vera do this?
----------
I am assuming Hand Sanitizer and ... |
How does Aloe Vera leaves a cool feeling on your skin? Why does it evaporate fast? |
The fundamental equation of thermodynamics, as us chemists (and chemical engineers!) are used to seeing it, is
$$ \mathrm{d}G = - S~\mathrm{d}T + V~\mathrm{d}P + \sum_{i}\mu_i~\mathrm{d}N_i$$
This gives the Gibbs free energy as a function of temperature, pressure, and composition, _assuming there are no other re... |
I was reading Peter Atkins' _Elements of Physical Chemistry_ where I came across this line:
>Bonds do not form **because** electrons tend to pair; bonds are **allowed** to form by the electrons pairing their spins.
What does this line mean? What does Atkins want to say through this line & why did he italize the w... |
"Bonds do not form because electron tends to pair; bonds are allowed to form by the electrons pairing their spins "- What does it mean? |
The fundamental equation of thermodynamics, as us chemists (and chemical engineers!) are used to seeing it, is
$$ dG = - S~dT + V~dP + \sum_{i}\mu_i~dN_i$$
This gives the Gibbs free energy as a function of temperature, pressure, and composition, _assuming there are no other relevant forces other than mechanical ... |
How does Aloe Vera leave a cool feeling on your skin? Why does it evaporate fast? |
I was reading some organometallics and I came upon the preparation of uranocene. It has two cylcooctatetraenide anions as ligands with a Uranium atom inbetween. The author has mentioned that the neutral cyclooctatetraene molecule is non aromatic and has a tub-shaped conformation but the anion is planar but aromatic. Wh... |
Why is cyclooctatetraene non planar but the cyclooctatetraenide anion planar? |
I wonder which fundamental forces act behind osmosis process? Sum of these forces oppose gravity force, like in this figure: ![enter image description here][1]
[1]: https://i.stack.imgur.com/0orO6.jpg
So I wonder what are these forces?
|
Are all the C-N single bonds in 2-bromo 1,3,5-trinitro benzene same or different? I am of the view that C1-N and C3-N is of the same bond length and it is more than C5-N bond length, due to steric hindrance. Am I right or am I missing out something?
Thank you in advance.
![structure of 2-bromo 1,3,5-trinitro benze... |
Are all the C-N single bonds in 2-bromo-1,3,5-trinitrobenzene same or different? I am of the view that the C1-N and C3-N bonds are of the same length and they are longer than the C5-N bond, due to steric hindrance. Am I right or am I missing out something?
Thank you in advance.
![structure of 2-bromo 1,3,5-trinitr... |
Are all the $\ce{C-N}$ single bonds in 2-bromo-1,3,5-trinitrobenzene the same or different? I am of the view that the $\ce{C_1-N}$ and $\ce{C_3-N}$ bonds are of the same length and they are longer than the $\ce{C_5-N}$ bond, due to steric hindrance. Am I right or am I missing out something?
Thank you in advance.
!... |
Take, for example, $\mathit{sp^3}$ hybridization. The wavefunction of each hybrid orbitals are given by:
$$\psi_1 = \psi_s + \psi_{p_x} + \psi_{p_y} + \psi_{p_z}\\\\\\ \psi_2 =\psi_s - \psi_{p_x} + \psi_{p_y} - \psi_{p_z}\\\\\\ \psi_3=\psi_s - \psi_{p_x} - \psi_{p_y} + \psi_{p_z}\\\\\\ \psi_4 = \psi_s + \psi_{p_x} ... |
How can actually hybrid orbitals be equivalent? |
This is not really a simple question at all, in fact, it is an interesting insight in chemical bonding. You make a valid assertion with your question:
> are ionic bonds just extremely polar covalent bonds?
**This answer is a simplistic way of looking at it.**
According to ChemGuide page [Electronegativity][... |
**Regarding your question:** "Is the resistance fixed, or can I do anything to lower it?"
With electrolysis there are two kinds of resistance. That is, there are kinds of work being performed. First is the product of electrolysis and depends on the chemistry involved, like H<sub>2</sub> and O<sub>2</sub> from 2H<sub... |
Old papers on chemical structures often contained "3D" renderings of the molecule by using 2 2D images and requiring the reader to go cross-eyed to get the 3D image. A good example I recently found was figure 2 from [Carter and Kraut, 1974](http://www.pnas.org/content/71/2/283.abstract), which I copied below:
. Real orbitals are the superposition of complex orbitals having definite magnetic quantum n... |
Why is real orbital used to define the orbital of hydrogenic atoms & not complex orbitals? |
Molecular mass has NO pertinence to BP, water and ammonia. Look up the BP of perfluorocyclohexane, hexafluorobenzene, and the hydrocarbons. If I want to volatize iron, ferrocene. If I want to volatize iron more, $\ce{Fe(hfac)_3}$ where the ligand is the bidentate enolate anion of 1,1,1,5,5,5-hexafluoro-2,4-pentanedi... |
> but the answer is opposite ,ie. B.P. of $\ce{CH3Cl}$ > B.P. of $\ce{CHCl3}$.
Really?
$\ce{CH3Cl}$ has a boiling point of **−24** °C. It is a **gas**.
$\ce{CHCl3}$ has a boiling point around 61 °C.
<hr>
Edit: **Your argumentation is valid, there was probably just some confusion in the notes.** |
Carbonic acid ($\ce{H2CO3}$) is known to be [soluble in water][1], and that this particular compound is [unstable][2], so much so that according to the 2014 article from Berkeley Lab: [New Insights on Carbonic Acid in Water][3], it only exists for a fraction of a second (300 nanoseconds according the article).
Recen... |
I'm finding it difficult to visualise the process of hybridisation. Taking the example of formation of $CH_4$, can it viewed as the collapsing of the p orbitals of the Carbon atoms as they get "heavier" on excitation even before the introduction of Hydrogen atoms or is it the collision with Hydrogen atoms that causes t... |
What Causes Atomic Orbitals to Hybridise? |
I'm finding it difficult to visualise the process of hybridisation. Taking the example of formation of $\ce{CH4}$, can it viewed as the collapsing of the p orbitals of the Carbon atoms as they get "heavier" on excitation even before the introduction of Hydrogen atoms or is it the collision with Hydrogen atoms that caus... |
Are all the $\ce{C-N}$ single bonds in 2-bromo-1,3,5-trinitrobenzene the same or different? I am of the view that the $\ce{C_1-N}$ and $\ce{C_3-N}$ bonds are of the same length and they are longer than the $\ce{C_5-N}$ bond, due to steric hindrance. Am I right or am I missing out something?
![structure of 2-bromo 1,... |
Will bridged compounds undergo SN1 reaction? |
Is there a trick or a formula that given a molecular formula, allows you to know exactly how many constitutional isomers can be formed with that many atoms? Or is it more of a trial-and-error technique?
I'm looking for something along the lines of $2^n$ of maximum number of possible stereo-isomers, where _n_ is the ... |
(OrgChem) Total number of constitutional isomers? |
While I was looking at the periodic table today, I realised that there were gases that were much lighter than helium such as hydrogen. If hydrogen is lighter than helium, why do we insist on using helium in balloons? |
I have a solution with **only** $\ce{CO_3^{2-}}$ ions and water.
What would happen with the carbonate ions if I were to evaporate the water of that solution (in a vacuum)?
|
Is there a formula to determine the total number of constitutional isomers? |
Atmospheric oxygen is in O2 and a gas. Then we inhale the air, our efficient lungs do the magic to filter out the oxygen and *push* them into the blood stream.
When we say hemo and globin transport the oxygen using the iron ions. In what state oxygen is transported in the blood? as a gas or a liquid or an ion? It is... |
What is the state (gas, liquid) of Oxygen in the blood? |
I have provided the name of cell in IUPAC
Zn|Zn2+(0.1M)||Zn2+(0.0 1M)|Zn How to write the last cell reaction for this cell? I can identify the oxidation and reduction reactions but when they are adding there is no formula to write.
anode Zn -> Zn2+ + 2e
cathode Zn 2+ + 2e -> Zn |
How to write the last cell reaction for the following cell? |
Consider the following electrochemical cell:
$$\ce{Zn|Zn^{2+}}(0.1~\mathrm{M})||\ce{Zn^{2+}}(0.01~\mathrm{M})\ce{|Zn}$$ How should I write the overall cell reaction for this cell? I can identify the oxidation and reduction reactions but when they are added, all the species cancel out, leaving my with no overall equati... |
what calculations are needed to convert ppm gas (N2O) concentrations in microgram nitrogen per gram dry soil basis? I measured the concentration of N2O in soil samples. I extracted a small gas sample from a container (the soil is kept in this container; the container has an head space of 80 cc). Then I injected the sma... |
What calculations are needed to convert $\ce{N2O}$ gas concentrations in ppm to micrograms of nitrogen per gram dry soil basis? I measured the concentration of $\ce{N2O}$ in soil samples. I extracted a small gas sample from a container (the soil is kept in this container; the container has an head space of 80 cc). The... |
It seems like glass-coated stir bars are a specialty item. Standard stir bars are coated in PTFE. Is PTFE resistant to all typical lab solvents? Or is there a reference to check to ensure it is inert to the chemicals being stirred? |
Are PTFE stir bars resistant to all lab solvents? |
The question asks whether a reaction will occur in the following case. If so, write a net ionic equation for the reaction:
> $\ce{(NH4)2SO4 (aq) + ZnCl2 (aq) ->}$
The book says that all possible combinations of positive and negative ions lead to water soluble compounds, all of the ions remain in solution. No re... |
While reading steriochemistry,I came to know that the stability and melting point of cis isomerism is less than trans isomerism. By searching on net I've found the reason behind that. But one question arises-why is the internal energy of cis isomerisom is more than trans isomerism? |
While reading about stereochemistry, I came to know that the stability and melting point of cis isomers is lower than trans isomers. By searching on net I've found the reason behind that. But one question arises - why is the internal energy of cis isomers bigger than of trans isomers? |
Whilst reading about stereochemistry, I came to know that the stability and melting point of cis isomers is lower than trans isomers. By searching on net I've found the reason behind that. But one question arises - why is the internal energy of cis isomers bigger than of trans isomers? |
I think this question cannot be answered so easily - your proposed reaction mechanism, however, looks good. A detailed explanation and "main reaction mechanism" can be found [here][1], page 192 (just search for "ethene" in the book). As you already indicate ethene reacts with a hydroxyl radical, followed by the additio... |
I'm growing grapehene on copper substrates and need to know the mass. The graphene is grown via chemical vapor deposition, amounts of reactants are not completely known. The best approach I've thought of is recording the mass of the substrate before and after using an analytical balance, but with the nature of the mate... |
I'm growing graphene on copper substrates and need to know the mass. The graphene is grown via chemical vapor deposition; amounts of reactants are not completely known. The best approach I've thought of is recording the mass of the substrate before and after using an analytical balance, but with the nature of the mater... |
Cupric oxide is black in colour.But when we are doing the practical of finding the percentage of oxygen by volume using ammonia,copper and ammonium chloride color of CuO turns to green.can you explain the reason for that?
I'm adding a another question here.why can't we usehydrochloric acid for ammonium chloride? |
why is cupric oxide seem to be green? |
Cupric oxide is black in colour.But when we are doing the practical of finding the percentage of oxygen in air by volume using ammonia,copper and ammonium chloride color of CuO turns to green.can you explain the reason for that?
I'm adding a another question here.why can't we usehydrochloric acid for ammonium chloride... |
Cupric oxide is black in colour.But when we are doing the practical of finding the percentage of oxygen in air by volume using ammonia,copper and ammonium chloride color of CuO turns to green.can you explain the reason for that? |
Cupric oxide is black, but when we find the percentage of oxygen in air by volume using ammonia, copper, and ammonium chloride, the color of CuO turns green. What is the reason for this?
I'm adding a another question here:
Why can't we use hydrochloric acid instead of ammonium chloride? |
Why is cupric oxide green? |
Cupric oxide is black, but when we find the percentage of oxygen in air by volume using ammonia, copper, and ammonium chloride, the color of $\ce{CuO}$ turns green. What is the reason for this?
I'm adding a another question here:
Why can't we use hydrochloric acid instead of ammonium chloride? |
The leaf of aloe vera is composed of three layers: 1) An inner clear gel that contains 99% water and rest is made of glucomannans, amino acids, lipids, sterols and vitamins. 2) The middle layer of latex which is the bitter yellow sap and contains anthraquinones and glycosides. 3) The outer thick layer of 15–20 cells ca... |
I understand that [molecular dipoles][1] are electric dipoles. And [electric dipole moment vectors][2] point from the negative to the positive charge.
In class we learned to draw these special molecular dipole arrows (with a "plus" at the beginning) that point from the positive to the negative partial charge. I also... |
If I am not mistaken, distilling water does not remove all possible impurities. Chemicals with boiling points less than $100\ \mathrm{^\circ C}$ will be transferred as well. Does the usual tap water contain such (I think there is at least fluoride.)? I read that activated carbon can be used to purify water as well. How... |
I plan to do a string of experiments on the kinetics of the decomposition of hydrogen peroxide. I’m going to see the effect of catalyst concentration on rate and the effect of varying hydrogen peroxide concentration on rate, which will then allow me to formulate a rate equation for the reaction.
I would also like t... |
My book says that, "Monocyclic substituted hydrocarbons are named as derivatives of benzene or compounds like cumene, toluene, xylene, etc. However, if the substituent introduced into such a compound is identical with the substituent already present in the compound, then the substituted compound is named as tge derivat... |
Is 3,5-diethyltoluene an accepted IUPAC name? |
My book says that
> Monocyclic substituted hydrocarbons are named as derivatives of benzene or compounds like cumene, toluene, xylene, etc. However, if the substituent introduced into such a compound is identical with the substituent already present in the compound, then the substituted compound is named as tge deriva... |
an ideal gas is at pressure $P$ and temperature $T$ in a box,which is kept in vacuum with in a large container. the wall of the box is punctured .what happens as the gas occupy entire container. the answer is it will remain same how it is possible?by what process this will happen? |
an ideal gas is at pressure $P$ and temperature $T$ in a box,which is kept in vacuum with in a large container. the wall of the box is punctured .what happens to temperature as the gas occupy entire container. the answer is it will remain same how it is possible?by what process this will happen? |
What calculations are needed to express the grams of an atom from a compound dissolved in aqueous solution? For example, I have a 0.5 M glucose aqueous solution and I want to know how many grams of O are in there. |
What calculations are needed to express the grams of an atom from a compound dissolved in aqueous solution? |
When $\ce{NaCl}$ is dissolved into water it breaks down into $\ce{Na+}$ and $\ce{Cl-}$. It stays in this form until the water evaporates and then the ions go back to normal $\ce{NaCl}$. So why does water with salt in it still taste like salt? I am asking because if the molecule $\ce{NaCl}$ is broken down into $\ce{Na+}... |
Have you ever tasted salt that was not dissolved in water? Think about this. Have you ever tasted ANYTHING that was not dissolved in, or in contact with, water? The answer is "No", unless you have the worst case of chronic dry mouth ever to exist in the history of humanity, and if you do have that terrible case of d... |
What calculations are needed to express the grams of an atom from a compound dissolved in aqueous solution? For example, I have a 0.5 M glucose aqueous solution and I want to know how many grams of O are in there.
I have tried to calculate in this way. MW glucose= 180.159 g/mol; AW C= 72; AW H= 12.09; AW O= 96... |
Avogadro stated that for any ideal gas, 1 mole of particles will occupy a specific volume at a specific ratio of pressure and temperature. So why doesn't this apply to a liquid or solid? |
Why not an Avogadro ' s principle for solid matter? |
What is the correct structure for the $\ce{NO2}$ 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 p... |
Why not an Avogadro's principle for solid matter? |
> And in what conditions can $\ce{H^{−}}$ occur?
In any phase. The hydride ion however doesn't stick around for long in water since it's _such_ a strong base. First, hydrogen isn't that electronegative to start with, so tacking on an extra electron isn't helping with its stability. Second, combination with an hydrog... |
Is purple paint more susceptible to UV damage than other colors? |
I've always been puzzled by this because my teachers happen to use only the KLMN method, but what is the difference between the KLMN and SPDF methods of finding electronic configuration? |
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