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Can we determine the amplitude of vibration of O-H bonds in water? |
So, at the anode of a fuel cell hydrogen is split into a positively charged proton and an electron. Then, there is the membrane which can let only protons through to the cathode, whereas electrons need to follow external circuit (effectively powering it).
Question: why do we need any other reaction on the cathode? I... |
>Why do we need two half reactions, one at the anode and another at the cathode?
The whole thing eventually grinds to a halt without the other reaction. The electrons generated at the anode travel through the circuit to the cathode. What happens then? Something needs to happen to the electron.
Additionally, wha... |
I wear corrective eyeglasses, and because of this, I frequently experience problems with fogging when I wear safety goggles. How can I prevent or reduce fogging?
The safety goggles I use are the standard-issue goggles supplied by the campus store, but I can use other goggles rated at least Z87+D3 ("+"=impact, "D3"=... |
Let's say I am seeking to find an alloy with certain properties, is there any method or process that enables one to backtrack from desired properties to actual structure and composition of a material? |
> My question is: is it possible to know the amplitude of
> oscillation/stiffness constant of a O−H bond?
**Yes.**
Your approach is along the right lines **but** -
The Hooke's Law formula you used
$$\mathrm{E = \frac{1}{2}kA^2}$$
is for the stretching of a spring. Hooke's law changes if the spring has... |
> My question is: is it possible to know the amplitude of
> oscillation/stiffness constant of a O−H bond?
**Yes.**
Your approach is along the right lines **but** -
The Hooke's Law formula you used
$$\mathrm{E = \frac{1}{2}kA^2}$$
is for the stretching of a spring. Hooke's law changes if the spring has... |
How could one calculate the Fermi level of a copper-nickel alloy? They are both structurally face-centered cubic, however how would this structure affect the Fermi level of the individual atom or the entirety of the material? |
This is going to be a long shot, and I might be wrong in any and all of my assumptions, be warned (... and please correct me). I might also be trivially right, I have no idea.
At equilibrium, each degree of freedom has the kinetic energy:
$ E = \frac{1}{2}k_\mathrm bT $
So, I have water at, say, $300\ \mathrm ... |
Two solutions were prepared.
'Solution A' being $\ce {Na2S4}$ prepared from aqueous $\ce {NaOH}$ and elemental sulfur, the mixture heated and additional sulfur added until sulfur remained as a precipitate.
'Solution B' being a solution of $\ce {FeSO4}$ and $\ce {Fe2(SO4)2}$ prepared from reacting steel wool with $\c... |
I want to know if I can use electronegativity in atoms to get the dipole moment of molecules. What I'm thinking is that dipole moments determine the polarity of molecules, right? So if I have a larger dipole moment than that means that there is a larger polarity of the molecule than the others.
Can you also see how ... |
Can you get Dipole Moment from Electronegativity? |
Baking Soda (sodium bicarbonate) + citric acid react when mixed with water to form some amount of carbon dioxide (CO2), I'm trying to find out what percent of the resulting reaction is carbon dioxide.. in other words, how much does it make? A lot? A little? |
Baking Soda + Citric Acid + Water = CO2, how much though? |
Let there be three species: a hydrated solid $H$, an anhydrous solid $A$, and a complete solvated (liquid) aqueous solution, $S$.
Your question is about differences in the two equilibria $\ce{H <=> S}$ and $\ce{A <=> S}$. Can $H$ really have a different solubility than $S$?
I think the answer is yes, but only if... |
This is a question from Atkin's Physical Chemistry Book.
**Question**
Suppose that 3mmol $N_29(g)$ occupies $36cm^3$ at $300K$ and expands to $60cm^3$. Calculate $\Delta G$ for the process.
**My Attempt**
I decided to split this process up into two separate process (I am not sure if this allowed. Please cor... |
This is a question from Atkin's Physical Chemistry Book.
**Question**
Suppose that 3mmol $\mathrm{N_2\,(g)}$ occupies $\mathrm{36~cm^3}$ at $\mathrm{300~K}$ and expands to $\mathrm{60~cm^3}$. Calculate $\Delta G$ for the process.
**My Attempt**
I decided to split this process up into two separate process (I... |
I have seen these terms being used almost interchangebly, but are decomposition and dissociation reactions the same ? |
Are decomposition and dissociation reactions the same? |
_I'm quite certain about the following, because it's from the related (german) woorkbook to the 4th (german) edition. The beneath numbering is from the linked online version, which should be the 9th english edition._
Your way to the solution is part of subsection **3.9 Properties of the Gibbs energy** and subsubsect... |
Why is it that ionic reactions I.e. compounds involving ionic compounds are faster than covalent reactions I.e. compunds involving covalent compounds even though the ionic bond is more stronger than the covalent bond hence more time will be required to break bond.? |
Here's the problem: ![enter image description here][1]
I've already know the 3600cm-1 indicates the -OH group and the 1640cm-1 indicates the C double-bond C alkene.
For the 13C NMR data: there are 4 different environments which the ones in the 100+ are sp2 carbons and the other two are sp3 carbons.
I have tried ... |
I'm not sure what you mean by 90% and 10%. If you mean 90% yield (i.e. 90% or more of the bicarbonate ions in sodium bicarbonate will become carbon dioxide), then yes, that will happen if there is enough acid. How much is enough acid? We'll get to that in a minute. If you mean something else, like 90% of the mass of th... |
Why is it that ionic reactions (i.e., reactions involving ionic compounds) are faster than covalent reactions (reactions involving covalent compounds), even though the ionic bond is stronger than the covalent bond and hence more time will be required to break the bond? |
Why are rates of reaction faster for ionic compounds than they are for covalent compounds? |
[![enter image description here][1]][1]
There is cyclopentyl attached to one terminal carbon atom and cyclohexyl attached to the other terminal carbon atom and there are three carbon atoms linking them. Since the cyclohexyl ring has the greatest number of carbon atoms, it should be the parent chain. So the name shou... |
What is the parent chain in this hydrocarbon? |
Baking Soda (sodium bicarbonate) + citric acid react when mixed with water to form some amount of carbon dioxide (CO2), I'm trying to find out what percent of created products is carbon dioxide; in other words, how much does reaction make? |
Baking soda (sodium bicarbonate) + citric acid react when mixed with water to form some amount of carbon dioxide gas ($\ce{CO2}$). I am trying to determine what percentage of the products is carbon dioxide: in other words, how much does reaction make? |
I want to know if I can calculate the dipole moment of a molecule given the electronegativity values for the atoms comprising it.
I think that dipole moments determine the polarity of molecules, so if one molecule has a larger dipole moment than another, the one with the larger dipole moment is more polar than the ... |
In the last exam we have been asked to rationalize the mechanism of the cyclopropylmethylene carbene cleavage into acetylene and ethylene.
[![enter image description here][1]][1]
In the lecture we discussed pericyclic reactions (cycloadditions, electrocyclic reactions, sigmatropic reactions, ene reactions). I don... |
I'm not sure what you mean by 90% and 10%. If you mean 90% yield (i.e. 90% or more of the bicarbonate ions in sodium bicarbonate will become carbon dioxide), then yes, that will happen if there is enough acid. How much is enough acid? We'll get to that in a minute. If you mean something else, like 90% of the mass of th... |
I'm not sure what you mean by 90% and 10%. If you mean 90% yield (i.e. 90% or more of the bicarbonate ions in sodium bicarbonate will become carbon dioxide), then yes, that will happen if there is enough acid. How much is enough acid? We'll get to that in a minute. If you mean something else, like 90% of the mass of th... |
Can mechanical agitation catalyze reactions?
It appears so, based on the following observation: We were using 10-micron hBN powder to impact-plate copper bearings (e.g., by running them together in a vibratory tumbler, and other similar processes). Even though the mechanical processes ran in a standard atmosphere a... |
Can reactions be mechanically catalyzed? |
I have made up an o-phthaldialdehyde (OPA) reagent according to [Handbook of HPLC page 715][1] that will be used to derivatize amino acids before an HPLC run. There is no information given on reagent storage, but the OPA crystals themselves must be stored in the fridge. However, storing this reagent in the fridge cause... |
Can mechanical agitation catalyze reactions? [It appears so](http://en.wikipedia.org/wiki/Mechanochemistry) (thanks to Mithoron for the pointer!).
We observed the following: We were using 10-micron hBN powder to impact-plate copper bearings (e.g., by running them together in a vibratory tumbler, and other similar p... |
How might ammonia be created in this mechanochemical reaction? |
Can mechanical agitation catalyze reactions? [It appears so](http://en.wikipedia.org/wiki/Mechanochemistry) (thanks to Mithoron for the pointer!).
We observed the following: We were using 10-micron hBN powder to impact-plate copper bearings (e.g., by running them together in a vibratory tumbler, and other similar p... |
Generally water soluble salts tend to 'fit between' the molecules of water such that the volume of the resulting solution does not increase much relative to the volume and added mass of the salt. So the result is that the solution generally has a higher density than pure water.
But are there any special cases; any s... |
Is there a soluble salt, or compound that when dissolved in water results in a solution with density less than pure water? |
I work in a restaurant where we dry age our uncut steaks in a cooler. Dry aging is a wonderfully complex process that improves the flavor of richly marbled steaks. Our particular type of aging cooler has a wall of himalayan pink salt (NaCl with other minierals and enough iron oxide to make a pink hue). Our process is e... |
The Salt Room, is there salt in the air? |
In short, no. The [vapor pressure of salt][1] is trivial compared to the grams of salt you would put on a steak when cooking it. I think your analysis is good- the most likely impact is that the salt modulates the humidity.
[1]: http://webbook.nist.gov/cgi/cbook.cgi?ID=C7647145&Mask=4&Type=ANTOINE&Plot=on#ref-2 |
Why are there no formal charges on the 1st compound? I am specifically referring to the nitrogen atom, which I would think should exhibit a +2 formal charge? However, in David Klein's organic chemistry textbook it is told that the 1st compound shows no formal charge anywhere. The second compound, of course, exhibits a ... |
Are there any formal charges in compound number 1? |
Why do ligands have such a small effect on overall absorption of the complex ion? |
What is the meaning of overpotential in the context of photocatalytic water-splitting? That is light drives charge separation inside TiO2 and the generated electrons and holes react with water to produce hydrogen and oxygen.
I have seen many papers talk about the high overpotential associated with the oxygen evolut... |
When a metal cation is complexed, there is strong UV-Vis absorption due to the splitting of its $d$ orbitals, thereby allowing electronic transitions.
My understanding is that ligands contribute very little to overall observed absorption. This is evident, for example, in copper solutions. Copper(II) chloride, copper... |
Why do ligands have such a small effect on overall absorption of a complexed ion? |
Freezing a full bottle of water tends to shatter the glass bottle. But what if you used something tougher than glass, like diamond? What would happen if you kept dropping the temperature, but restrained the liquid volume so it couldn't freeze? And what sort of force would the liquid exert on the container's walls?
|
What happens if you cool water in a container too small for it to freeze? |
Good question. Let's assume the container is infinitely strong, non-deformable, and constant in volume. Let's also assume that cooling the water is an equilibrium process -- that way, we won't have any [supercooling](https://www.youtube.com/watch?v=Fot3m7kyLn4).
At equilibrium, the first tiny bit of ice that fre... |
Is it possible that some Chemical Reactions can't be balanced through Redox Method? Because it seems to me that the elements on the Reactants side have the same oxidation states with the Product side. |
Is REDOX METHOD applicable to ALL CHEMICAL REACTIONS? |
Is it possible that some chemical reactions can't be balanced through the redox method? Because it seems to me that the elements on the reactants side have the same oxidation states with the product side. |
Is the redox method applicable to all chemical reactions? |
Why are there no formal charges on the 1st compound? I am specifically referring to the nitrogen atom, which I would think should exhibit a +2 formal charge? However, in David Klein's organic chemistry textbook it is said that the 1st compound shows no formal charge anywhere. The second compound, of course, exhibits a ... |
How to find the concentrations of the acid-base equilibrium between sulfuric acid and sulfur dioxide for a known pH using Octave? |
im supposed to produce dry and pure oxygen and im using the decomposition of hydrogen peroxide and using a catalyst which is manganese dioxide so the equation is this: 2 H2O2 (aq) → 2 H2O (l) + O2 (g)
The oxygen gas produced will be collected in a bottle by a method known as the downward displacement of water. but ... |
I'm supposed to produce dry and pure oxygen using the decomposition of hydrogen peroxide with a manganese dioxide catalyst.
2 H2O2 (aq) → 2 H2O (l) + O2 (g)
The gas will be collected in a bottle by downward displacement of water. How can I safely move the oxygen gas through the drying agent without mixing in atm... |
I'm supposed to produce dry and pure oxygen using the decomposition of hydrogen peroxide with a manganese dioxide catalyst.
$$\ce{2 H2O2 (aq) → 2 H2O (l) + O2 (g)}$$
The gas will be collected in a bottle by downward displacement of water. How can I safely move the oxygen gas through the drying agent without mixi... |
In making cast iron from pig iron - the cruder form of iron - coke and limestone are added to pig iron and scrap iron in a furnace. Cast iron is more refined form of iron and has lesser carbon content as well. What exactly occurs in this process of making cast iron - what reactions happen in the furnace? Why is coke ... |
I have quoted the following answers from [the UC Davis ChemWiki page on "The Extraction of Iron."](http://chemwiki.ucdavis.edu/Inorganic_Chemistry/Descriptive_Chemistry/Elements_Organized_by_Block/3_d-Block_Elements/1b_Properties_of_Transition_Metals/Metallurgy/The_Extraction_of_Iron)
>Why is coke added as well, whe... |
Is there a chemical property (perhaps electron affinity?) that can be used to predict where a substance would fall in a triboelectric series such as [this one][1]? Or would the cause of the charge imbalance vary on a case by case basis?
[1]: https://www.trifield.com/content/tribo-electric-series/ |
Is there a specific chemical property or concept that explains/predicts the triboelectric series? |
Freezing a full bottle of water tends to shatter the glass bottle. What if you used something tougher than glass, like diamond? What would happen if you kept dropping the temperature, but restrained the liquid volume so it couldn't freeze and what sort of force would the liquid exert on the container's walls?
|
The Sandmeyer reaction is an extremely useful reaction for the functionalization of aromatic rings through a diazonium intermediate. For conversion of a diazonium intermediate to the corresponding chloride, bromide, or cyanide, the copper(I) salt is used. Surprisingly (to me at least) for iodination, potassium iodide i... |
Why use potassium iodide instead of copper iodide in Sandmeyer reaction? |
My book doesn't classify them as positional isomers but the position of the methoxy group is different in both the molecules. So, I guess they should be positional isomers.
I understand that the two compounds are metamers. But can't a metamer be a positional isomer? |
Is 1-methoxy-2-methylpropane a positional isomer of 2-methoxy-2-methylpropane? |
In the question the following electronic configuration and corresponding picture are given:
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/GtDI3.png
How does this image correspond with the electronic configuration?
My trail of thought so far:
Sin... |
How do the given electronic configuration and structural formula of an acid oxide correspond? |
The structure of DDT is
[![enter image description here][1]][1]
One of the benzene molecules should be the parent chain as it has greater number of Carbon atoms than the straight chain(which has just two Carbon atoms.)
Taking Benzene as the parent chain, the name of the compound should be
1-Chloro-4-((1'-(4"-... |
What is the IUPAC name of DDT? |
The following electronic configuration and drawing of the structure are given:
$\mathrm{(1s)^2 (2s)^2 (2p)^6 (3s)^2 (3p)^6 (3d)^{10} (4s)^2 (4p)^4}$
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/GtDI3.png
How does this image correspond with the electronic configuration?
My train... |
How does the electronic configuration for this acid oxide correspond to its structure? |
What is the rationale for the IUPAC name for DDT? |
I'm supposed to produce dry and pure oxygen using the decomposition of hydrogen peroxide with a manganese dioxide catalyst.
$$\ce{2H2O2 (aq) → 2H2O (l) + O2 (g)}$$
The gas will be collected in a bottle by downward displacement of water. How can I safely move the oxygen gas through the drying agent without mixing... |
Your code seems to be calculating the _differences_ between a guessed concentration vector `x` and a calculated concentration vector. These differences in concentrations between guessed and calculated are `y`. For example, the guessed pH is apparently `x(1)`, and the calculated pH is `10^(-pH)`. The difference betwe... |
Good question. Let's assume the container is infinitely strong, non-deformable, and constant in volume. Let's also assume that cooling the water is an equilibrium process -- that way, we won't have any [supercooling](https://www.youtube.com/watch?v=Fot3m7kyLn4).
At equilibrium, the first tiny bit of ice that fre... |
The structure of DDT is
[![enter image description here][1]][1]
One of the benzene molecules should be the parent chain as it has a greater number of carbon atoms than the straight chain (which has just two carbon atoms). Taking benzene as the parent chain, I think that the name of the compound should be 1-Chlor... |
What is the rationale of the IUPAC name for DDT? |
I understand why cysteine has a pka of 8.3. But the pka of thiol ( from NAC) is 9.27. There is a acetylgroup attached to the nitrogen, isnt this Inductive so a lower pka?
Grtz |
Why is the pka of thiol group from NAC higher then the pka from Cysteine? |
I understand why cysteine has a p$K_{\rm a}$ of 8.3. But the p$K_{\rm a}$ of thiol in N-acetylcysteine is 9.27. Since there is an acetyl group attached to the nitrogen, doesn't this lower the p$K_{\rm a}$ *via* the inductive effect? |
Why is the pKa of the thiol group in N-acetylcysteine higher then the pKa of the thiol group in cysteine? |
Lithium batteries seem to be mainstream now, offering high energy density, high output current capability.
Stepping down the periodic table there are alkali metals with greater electronegativity than Lithium: sodium and potassium, etc.
So why not sodium and potassium batteries. Can't these offer higher energy de... |
Lithium batteries a reality - why not sodium, pottasium batteries? |
I understand why cysteine has a $pK_{\mathrm a}$ of 8.3. But the $pK_{\mathrm a}$ of thiol in N-acetylcysteine is 9.27. Since there is an acetyl group attached to the nitrogen, doesn't this lower the $pK_{\mathrm a}$ *via* the inductive effect? |
I would like to know what reaction occurs when soaking a piece of meat into apple cider vinegar? and How does it happen!
I read a topic which was about bad repetition of apple cider vinegar, that can actually " cook " your skin texture. |
what reaction occurs when soaking a piece of meat into apple cider vinegar? |
I've just learned how to predict the shapes of molecules in class today.
I would like to ask is there anyway to find the no of bond pairs and lone pairs without drawing dot-and-cross diagram? I hope I can get an clear explanation. Thanks in advance. |
I would like to know what reaction occurs when soaking a piece of meat in apple cider vinegar. Additionally, how does it happen?
I read a topic which was about the bad reputation of apple cider vinegar, which can actually "cook" your skin texture. |
What reaction occurs when soaking a piece of meat in apple cider vinegar? |
I've just learned how to predict the shapes of molecules in class today.
I would like to ask is there anyway to find the number of bond pairs and lone pairs without drawing a dot-and-cross diagram? |
I've just learned how to predict the shapes of molecules in class today using VSEPR theory.
I would like to ask is there anyway to find the number of bond pairs and lone pairs without drawing a dot-and-cross diagram? |
Ozone readily decomposes when impacted by uv light.
Sulfur dioxide, having the same bond structure and valence electrons in each atom as ozone, is much more stable.
Would someone please help me understand what makes sulfur dioxide a more stable compound?
Thanks! |
Why are the resonant bonds in sulfur dioxide more stable than the resonant bonds in ozone? |
Ozone readily decomposes when impacted by UV radiation.
Sulfur dioxide, having the same bond structure and valence electrons in each atom as ozone, is much more stable.
Would someone please help me understand what makes sulfur dioxide a more stable compound? |
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