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Well, this is a rather obvious development (in retrospect, that is). We had an $sp^3$ carbon with tetrahedral bonds, and it made diamond. We had an $sp^2$ carbon with trigonal bonds, and it made graphite. What if we just had a [linear $sp$ carbon][1]?
Such thoughts have been around for more than quite a while. Theor... |
Let's take the following reaction that has reached equilibrium
$$\ce{CaCO3 (s) <=> CaO (s) + CO2 (g)}$$
What can be done to increase the yield of calcium oxide ?
My initial thought was to remove the carbon dioxide produced in the reaction mixture. I understand that this is correct since, according to Le Chatel... |
>I believe have found a answer.
It's valid mathematically, make sense physically but I don't know if chemically is true.
I posted to community appreciation.
There we go!
----------
**The reactions**
1. *ionization of weak acid*:
$$\ce{HA + H2O <=> H3O+ + A-}\qquad K_\ce{a}=\frac{\ce{[H3O+][A-]}}{\ce{[HA]}}... |
Why are B-O-H and B-O-C angles in B(OH)$_3$ and B(OCH$_3$)$_3$ respectively are higher than normal? |
Why are B-O-H and B-O-C angles in B(OH)3 and B(OCH3)3, respectively are higher than normal? |
$r_0$ is the average bond length of the lowest vibrational state,<br>
$r_e$ is the location where the potential is lowest.
For a perfect harmonic oscillator, these are the same (notice that the peak probability is exactly at the minimum of the potential):
[![enter image description here][1]][1]
What is the la... |
What is the biggest known difference between $r_e$ and $r_0$? |
why is coupling reaction between aryldiazonium chloride and aniline carried out in a mild basic medium and not under acidic medium?
according to me it can performed in both mediums |
coupling reaction is performed in acidic or basic medium? |
Why is coupling reaction between aryldiazonium chloride and aniline carried out in a mild basic medium and not under acidic medium?
According to me, it can be performed in both mediums. |
Is coupling reaction performed in acidic or basic medium? |
> Which of the following compound has highest enol content?
> [![a: acetylacetone; b: 1‐phenyl‐1,3‐butanedione; c: dibenzoylmethane; d: 3‐methylpentane‐2,4‐dione][1]][1]
The answer is an option (**c**) and I think the reason behind it is that there are two phenyl groups attached to it, hence there will be a good ... |
Which has the highest enol content? |
> $\pu{1 L}$ of an aqueous solution of urea having density $\pu{1.06 g mL-1}$ is found to have elevation in boiling point $\Delta T_\mathrm{b} = \pu{0.5 °C}.$ If the temperature of this solution is increased to $\pu{101.5 °C},$ then calculate the amount of water which must have vaporized by doing so. Ebullioscopic cons... |
In *Concise Inorganic Chemistry* by JD Lee (4th edition; adapted by Sudarshan Guha), page 78 under the topic "Back Bonding" it is given:
> CHCl$_3$ is more acidic than CHF$_3$ which is explained as follows:
> CHCl$_3$ $\rightleftharpoons$ H$^+$ + $^-$CCl$_3$
> CHF$_3$ $\rightleftharpoons$ H$^+$ + $^-$CF$_3$
... |
Why is trichloromethane more acidic than trifluoromethane? |
Which requires more ionization energy
Ne or Ne+?
It seems to me like it should be Neon because of Noble gas configuration but the **answer given is Ne+** ...does this anything to do with size of the atom shrinking?
Is this because cationic counterparts always have more ionization energy than their neutral counterpart... |
A few days ago, in my chemistry lab class, I performed an experiment aimed at extracting and identifying DNA. The class is mostly practical oriented, so I thought of asking my theoretical doubts on ChemSE.
First of all, let me explain the experiment:
We used onion extract, sodium dodecyl sulfate (SDS) solution, ... |
> Which requires more ionization energy: $\ce{Ne}$ or $\ce{Ne+}?$
It seems to me like it should be neon because of noble gas configuration, but the answer given is $\ce{Ne+}.$ Does this anything to do with size of the atom shrinking?
Is this because cationic counterparts always have more ionization energy than th... |
In *Concise Inorganic Chemistry* by JD Lee (4th edition; adapted by Sudarshan Guha), page 78 under the topic "Back Bonding" it is given:
> $\ce{CHCl3}$ is more acidic than $\ce{CHF3}$ which is explained as follows:
> $$
\begin{align}
\ce{CHCl3 &<=> H+ + ^-CCl3}\\
\ce{CHF3 &<=> H+ + ^-CF3}
\end{align}
$$
>... |
> Does this anything to do with size of the atom shrinking?
Yes, precisely; this is one way of putting it. Another way is to say that because one electron has been removed, the remaining electrons are less shielded from the nuclear charge: therefore, the effective nuclear charge increases, and the remaining electron... |
How Benzyl alcohol gives peak at m/z = 79? |
I would like to make colloidal silver to kill mold.
I think 100ppm (weight) would be nice.
I read a paper on it and in it they used citric acid+destilled water as fluid, two silver plates as electrodes, 300v (50Hz Ac to reduce oxide buildup on electrodes), N2H2 as reducing agent and a surfactant to encapsulate the u... |
According to AIITS exam answer key, it was given that the following compound decarboxylates on heating:
[![cyclohexane-1,2-dicarboxylic acid][1]][1]
Then, I read [Why are beta-ketoacids better at decarboxylation than gamma or delta?](https://chemistry.stackexchange.com/questions/53879/why-are-beta-ketoacids-bette... |
Why does the d orbital size decreases on addition of electrons? |
I would like to make colloidal silver to kill mold. I think $\pu{100ppm}$ (weight) would be nice. I read a paper on it and in it they used citric acid + distilled water as fluid, two silver plates as electrodes, $\pu{300v}$ ($\pu{50Hz}$ Ac to reduce oxide buildup on electrodes), $\ce{N2H2}$ as reducing agent and a surf... |
I recently read about Chaos Theory and was wondering that if a chemical reaction results in or shows characteristics of chaos (I found a few examples of such reactions [here][1])
Will we able to attain a state of equilibrium? If yes will the system oppose this state and move away or stay in a dynamic equilibrium?
... |
I recently read about Chaos Theory and was wondering that if a chemical reaction results in or shows characteristics of chaos (I found a few examples of such reactions [here][1])
> Chaos theory concerns deterministic systems whose behavior can in principle be predicted. Chaotic systems are predictable for a while and ... |
I recently read about Chaos Theory and was wondering that if a chemical reaction results in or shows characteristics of chaos (I found a few examples of such reactions [here][1])
> Chaos theory concerns deterministic systems whose behavior can in principle be predicted. Chaotic systems are predictable for a while and ... |
According to bents rule in pentagonal bipyramidal more electronegative element is placed on the axial position ...so between Cl and Och3 which should be placed on axial as oxygen is more electronegative but ch3 would reduce it's overall electronegativity due to its +I effect...but my teacher said that Och3 should still... |
As far as I know usually CrO3 and KMnO4 are used for this scope, but can other oxidizers such as H2O2 be used? |
Can an alcohol oxidation to ketone happen with H2O2? |
According to FIITJEE's Sankalp Test-II answer key, it was given that the following compound decarboxylates on heating:
[![cyclohexane-1,2-dicarboxylic acid][1]][1]
Then, I read [Why are beta-ketoacids better at decarboxylation than gamma or delta?](https://chemistry.stackexchange.com/questions/53879/why-are-beta-... |
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contains [trimethylamine-*N*-oxide][1] $\ce{(CH3)3N-O}$,
that after fish death gets enzymatically reduced to [trimethylamine][2] $\ce{(CH3)3N}$... |
In *Concise Inorganic Chemistry* by J.D.Lee (Adapted by Sudarsan Guha, Fourth Edition), on page 82, under section 3.8 - Types of Covalent Bonds (Sigma and Pi Bonds) it is given (for Sulphur dioxide molecule):
> The $\pi$ bonds do not alter the shape, but merely shorten the bond lengths. The bond angle is reduced fr... |
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contains [trimethylamine-*N*-oxide][1] $\ce{(CH3)3N-O}$,
that after fish death gets enzymatically reduced to [trimethylamine][2] $\ce{(CH3)3N}$... |
In *Concise Inorganic Chemistry* by J.D.Lee (Adapted by Sudarsan Guha, Fourth Edition), on page 83, under the topic "Bridge Bonding" it is given for diborane ($B_2H_6$):
> The $d_{B-H}($terminal bonds$)<d_{B-H}($bridge bonds$)$
> The energy required to replace hydrogen atoms from the bridged position is more than... |
Why are bridge bonds weaker than terminal bonds in diborane? |
According to bents rule in sp3d more electronegative element is placed on the axial position ...so between Cl and Och3 **in SCl2(OCh3)2** which should be placed on axial as oxygen is more electronegative but ch3 would reduce it's overall electronegativity due to its +I effect...but my teacher said that Och3 should sti... |
Do you have any information about chemical resistance of hexa-functional aromatic urethane acrylate?
I want to know what solvents can solve aromatic uretan resins.
|
I study on a project that need to know what is the solvent of aromatic uretane? |
I recently read about Chaos Theory and was wondering if a chemical reaction results in or shows characteristics of chaos (I found a few examples of such reactions [here][1])
> Chaos theory concerns deterministic systems whose behavior can in principle be predicted. Chaotic systems are predictable for a while and the... |
As far as I know, usually $\ce{CrO3}$ and $\ce{KMnO4}$ are used for this scope, but can other oxidizers such as $\ce{H2O2}$ be used? |
Can an alcohol oxidation to ketone happen with hydrogen peroxide? |
Do you have any information about chemical resistance of hexa-functional aromatic urethane acrylate?
I want to know what solvents can solve aromatic urethane resins.
|
What solvents can solve aromatic urethane resins? |
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contain [trimethylamine-*N*-oxide][1] $\ce{(CH3)3N-O}$ that, after death, gets enzymatically reduced to [trimethylamine][2] $\ce{(CH3)3N}$, the sour... |
In *Concise Inorganic Chemistry* by J.D.Lee (Adapted by Sudarsan Guha, Fourth Edition), on page 82, under section 3.8 - Types of Covalent Bonds (Sigma and Pi Bonds) it is given (for Sulphur dioxide molecule):
> The $\pi$ bonds do not alter the shape, but merely shorten the bond lengths. The bond angle is reduced fr... |
In *Concise Inorganic Chemistry* by J.D.Lee (Adapted by Sudarsan Guha, Fourth Edition), on page 82, under section 3.8 - Types of Covalent Bonds (Sigma and Pi Bonds) it is given (for Sulphur dioxide molecule):
> The $\pi$ bonds do not alter the shape, but merely shorten the bond lengths. The bond angle is reduced fr... |
If 2 electrons undergo destructive interference (as they show wave nature) will they disappear or will they have no wave nature left? |
**Case -1**
In a free expansion of an ideal gas in a region or container, we cannot trace a pressure-volume path since the pressure, temperature and volume of the gas fluctuate unpredictably when the gas fills the region (container).
But since entropy is a state property, the difference in entropy must depend onl... |
There are claims that the bamboo fiber has inherent antibacterial properties due to "bamboo kun".
However I could not find anywhere what is the chemical composition of this "bamboo kun" and also no evidence to substantiate the antibacterial claims.
Does anybody know if bamboo kun is a myth or it really has a known ... |
what is the structure of bamboo kun? |
Some people define a "closed system" as one that can exchange neither heat nor work not mass with the broader surroundings. Others, like us engineers, define a "closed system" as on that can exchange both heat and work with its surroundings, but not mass. We engineers call a system that can exchange neither heat nor ... |
The mathematics of quantum mechanics predicts an unevenness of the observation, similar to wave equations in that there are points where high values of electron density/reaction and low (~zero) values occur. If you have places (~50% of the places) where "interference" has yielded zero electron density/reaction, then th... |
Eliminate the salt bridge. Test Al and Pb in a) Al(NO3)3 solution and b) (separately) Pb(NO3)2 solution. The salt bridge is for purity of thought and separation of the electrochemical reactions. A third possibility is to put an Al and a Pb electrode in HNO3 solution: any output voltage?
Just try to get a cell going.... |
For the following question:
$\mathrm{1g}$ of $\ce{Mg(OH)2}$ is completely dissolved in $\mathrm{25}$ mL of $\mathrm{0.5}$ M $\ce{HCl}$. This solution is then titrated with $\mathrm{0.1}$ M $\ce{NaOH}$, and it takes $\mathrm{40}$ mL of $\ce{NaOH}$ to reach the end point. What volume of $\mathrm{0.5}$ M $\ce{H2SO4}... |
According to bents rule in sp3d more electronegative element is placed on the axial position ...so between Cl and Och3 **in SCl2(OCh3)2** which should be placed on axial as oxygen is more electronegative but wouldn't ch3 reduce it's overall electronegativity due to its positive inductive effect...but my teacher said ... |
According to Bent's Rule in sp3d more electronegative element is placed on the axial position,so between Cl and OCH3 **in SCl2(OCH3)2** which should be placed on axial as oxygen is more electronegative but wouldn't ch3 reduce it's overall electronegativity due to its positive inductive effect,but my teacher said that... |
According to Bent's rule, in $\mathrm{sp^3d}$ more electronegative element is placed on the axial position, so between $\ce{Cl}$ and $\ce{OCH3}$ in $\ce{SCl2(OCH3)2}$ which should be placed on axial as oxygen is more electronegative, but wouldn't $\ce{CH3}$ reduce its overall electronegativity due to its positive induc... |
Which substitutent should be placed on axial position in SCl2(OCH3)2? |
For the following question:
$\mathrm{1g}$ of $\ce{Mg(OH)2}$ is completely dissolved in $\mathrm{25}$ mL of $\mathrm{0.5}$ M $\ce{HCl}$. This solution is then titrated with $\mathrm{0.1}$ M $\ce{NaOH}$, and it takes $\mathrm{40}$ mL of $\ce{NaOH}$ to reach the end point. What volume of $\mathrm{0.5}$ M $\ce{H2SO4}... |
I recently read about Chaos Theory and was wondering if a chemical reaction results in or shows characteristics of chaos (I found a few examples of such reactions [here][1])
> Chaos theory concerns deterministic systems whose behavior can in principle be predicted. Chaotic systems are predictable for a while and the... |
Molecular dynamics (Mac OSX user): what software can I use to plot RDFs for NPT simulations? VMD only works for NVT (constant volume) |
In *Concise Inorganic Chemistry* by J.D.Lee (Adapted by Sudarsan Guha, Fourth Edition), on page 83, under the topic "Bridge Bonding" it is given for diborane $(\ce{B2H6}):$
> The $d_\ce{B-H}(\text{terminal bonds}) < d_\ce{B-H}(\text{bridge bonds})$
> The energy required to replace hydrogen atoms from the bridged ... |
How Does Benzyl Alcohol Produce a Peak at m/z = 79? |
A few days ago, in my chemistry lab class, I performed an experiment aimed at extracting and identifying DNA. The class is mostly practical oriented, so I thought of asking my theoretical doubts on ChemSE.
First of all, let me explain the experiment:
We used onion extract, sodium dodecyl sulfate (SDS) solution, ... |
There are claims that the bamboo fiber has inherent antibacterial properties due to "bamboo kun".
However I could not find anywhere what is the **chemical composition** of this "bamboo kun" and also **no evidence** to substantiate the antibacterial claims.
Does anybody know if bamboo kun is a myth or it really has ... |
There are claims that the bamboo fiber has inherent antibacterial properties due to "bamboo kun".
However I could not find anywhere what is the **chemical composition** of this "bamboo kun" and also **no evidence** to substantiate the antibacterial claims.
Does anybody know if bamboo kun is a myth or it really has ... |
Can someone recommend HPLC columns for compounds which are not soluble in no- or low polar solvents (hexane, isopropanol, toluene, and dichloromethane)? |
I conducted an experiment in which 10mL of dilute hydrochloric acid was added to a beaker, and this acid was heated up to room temperature (22°C) using a Bunsen burner. 0.25 grams of calcium carbonate was then added to the beaker, and the time taken for it to dissolve (stop bubbling) was recorded. This was repeated at ... |
Why are bridge bonds weaker than terminal bonds in diborane and, H-B-H terminal bonds larger than that of bridging bonds? |
Why are bridge bonds weaker than terminal bonds in diborane and, H-B-H terminal bond angles larger than that of bridging bond angles? |
Why are bridge bonds weaker than terminal bonds and, H-B-H terminal bond angles larger than H-B-H bridging bond angles in diborane? |
> Which of the two structures is more stable?
> [![c: (3‐methylcyclohex‐1‐en‐1‐yl)benzene; d: (5‐methylcyclohex‐1‐en‐1‐yl)benzene][1]][1]
As far as I know, alkenes with a greater number of hyperconjugating structures are more stable. Hyperconjugation has a greater stabilizing effect than inductive effect. So, (**... |
Which of the two structures is more stable? |
I have read some other posts explaining what multi-reference and multi-configuration are with regards to the wave-function (such as [What exactly is meant by 'multi-configurational' and 'multireference'?](https://chemistry.stackexchange.com/q/103387)).
However, what does it mean for a molecule specifically to exhib... |
I'm writing something related to basicity and came across few papers that distinguish thermodynamic and kinetic basicity.
"In particular, the study of hydrogen bonding (H-bonding) within proton sponges has provided rigorous knowledge into the inter-related roles of symmetry, resonance, and aromaticity in H-bonding,... |
I conducted an experiment in which $\pu{10mL}$ of dilute hydrochloric acid was added to a beaker, and this acid was heated up to room temperature ($\pu{22 ^\circ C}$) using a Bunsen burner. Then, $\pu{0.25 g}$ of calcium carbonate was then added to the beaker, and the time taken for it to dissolve (stop bubbling) was r... |
I'm writing something related to basicity and came across few papers that distinguish thermodynamic and kinetic basicity.
"In particular, the study of hydrogen bonding (H-bonding) within proton sponges has provided rigorous knowledge into the inter-related roles of symmetry, resonance, and aromaticity in H-bonding,... |
So the cathode is magnesium and the anode copper. The question asks why silver nitrate would not be a good electrolyte. I am confused. Also is the anode always inert in these cells? |
I have worked on a computational project where I had to study the sites of deprotonation in this molecule:
[![enter image description here][1]][1]
When deciding between mechanisms I had to consider both thermodynamic and kinetic. For example, I had this case: deprotonations of two different hydrogens(bond with N ... |
While studying dipole moment in organic chemistry, I got stuck at a particular statement written in the book :
> Symmetrical molecules without lone pairs of electrons will have $\mu = 0.$
The main problem was, why would they have $\mu =0$ ?
What type of Symmetrical molecules are possible?
The book gave ... |
It depends on what you define as a bond. A three-center two electron bond is in general stronger than an ordinary two-center bond because delocalizing the bond over three atoms instead of two makes the bonding MO more stable. But, the bridge bond is also shared between two linkages so each individual linkage has less... |
It depends on what you define as a bond. A three-center two electron bond is in general stronger than an ordinary two-center bond because delocalizing the bond over three atoms instead of two makes the bonding MO more stable. But, the bridge bond is also shared between two linkages so each individual linkage has less... |
What is the Reactivity of Chlorodifluoromethane (R22 refrigerant)? |
As Ed said, that both copper and magnesium will reduce silver ions to elemental silver (you have to justify why in your answer. Hint: Look at the electrochemical series and compare the position of Mg, Cu, and Ag half cells. Another fundamental aspect is that one cannot apply Nernst equation if the metal dips in anythin... |
Try searching Google Scholar and write HPLC separation and the names of your compounds. You will find plenty of publications and of course column names. If your compounds are new, you should test the solubility in MeOH, ACN, and 50:50 MeOH/H2O and 50:50 ACN/H2O. Do they dissolve in such solvents systems? If they do, yo... |
Chlorine gas will not normally react with oxygen gas directly at STP. However, would the two react at standard pressure and 600 degrees Centigrade? |
We had a malfunction with the chlorination system at our pool. There was a reaction between the Calcium Hypochlorite tablets and EITHER CO2, Carbonic Acid, or Muratic Acid. There was a definite malfunction that led undetermined amounts of CO2, (or a mixture of that gas dissolved into water, carbonic acid?) into the t... |
Was it CO2 or Muratic Acid? |
According to Bent's rule, in $\mathrm{sp^3d}$ more electronegative element is placed on the axial position, so between $\ce{Cl}$ and $\ce{OCH3}$ in $\ce{SCl2(OCH3)2}$ which should be placed on axial as oxygen is more electronegative, but wouldn't $\ce{CH3}$ reduce its overall electronegativity due to its positive induc... |
Thermodynamics has always been a tough thing for me. There are lots of assumptions in this subject (those assumptions, I know, are necessary,I know the science of thermodynamics is a very practical science).
First Law of Thermodynamics states mathematically :-
$$\Delta U = q + W $$ (with proper sign conventions m... |
> Why thermodynamical equations are just for gases?
They are not. The equation $\Delta U = q + P\Delta V$ applies to any phase (gas, liquid, solid...) when *only* pV work is done. In the particular form of the equation you present, the pressure is in addition constant during the work.
Gases are (1) an easy way ... |
> Why thermodynamical equations are just for gases?
They are not. The equation $\Delta U = q + P\Delta V$ applies to any phase (gas, liquid, solid...) when *only* pV work is done. In the particular form of the equation you present, the pressure is in addition constant during the work.
Gases are (1) an easy way ... |
> Why thermodynamical equations are just for gases?
They are not. The equation $\Delta U = q + P\Delta V$ applies to any phase (gas, liquid, solid...) when *only* pV work is done. In the particular form of the equation you present, the pressure is in addition constant during the work.
Gases are (1) an easy way ... |
$1.$After adding two or more numbers, the number of digits after the decimal in the result=Least no. of digits after the decimal in the numbers being added.
$2.$After multilplying two numbers, no. of significant figures in a result= no. of significant figures in a number with least no. of significant figures, out of th... |
It depends on what you define as a bond. A three-center two electron bond is in general stronger than an ordinary two-center bond because delocalizing the bond over three atoms instead of two makes the bonding MO more stable. But, the bridge bond is also shared between two linkages so each individual linkage has less... |
I was taught to use Occam's razor whenever in doubt over an octet expansion, being told it never happened when, for example, dative bonds could resolve the issue with a regular octet. This seems to fit what users here say about the recent paradigm shift on "hypervalent" molecules that "[it is now known, that for almost... |
Is Octet Expansion appropriate when regular Octet bonding is possible (such as using dative bonds)? |
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