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So I am using electrolysis to remove rust from a fuel tank. The tank is the cathode and a sacrificial anode is inserted where the fuel pump normally goes. It's not practical to put it anywhere else.
However, the fuel tank has internal baffles, apparently for anti-slosh. They have continuity with the tank, i.e. t... |
Electrolysis for rust removal: is "line of sight" a showstopper? |
> why is dH=dE at constant volume?
It isn't, and nowhere in the problem or answer is this implied.
First of all some definitions.
For a combustion reaction, the *enthalpy* change can be equated with the heat of combustion at constant pressure, whereas the *internal energy* is the heat of combustion at constan... |
What does acidity of para-alkyl substituted phenols depend on? |
Out of the four equations that you have, you need to find $\Delta H^\circ_\mathrm f$ of $\ce{MgO}$, or rather, the $\Delta H$ value of the reaction
$$\ce{Mg(s) + 1/2O2(g) -> MgO(s)} \tag{1} \label{1}$$
Why is this? This is because of the definition of heat of formation is as follows:
> **Standard heat of for... |
I have that $100$ mM of K$_3$Fe(CN)$_6$ is dissolved in equimolar of the organic ion (which I assume is HCN). In the solution Fe(CN)$_6$$^{3-}$ reacts to form Fe(CN)$_6$$^{4-}$.
The formation of Fe(CN)$_6$$^{4-}$ as a function of time is measured in a Na$_2$SO$_4$ (which does not take part in the reaction) solution... |
I'm attempting to answer a question from my textbook, however the answer that the textbook provides doesn't make sense to me.
[![The question][1]][1]
In my mind, this dilution would instantly decrease the concentration of the reactants and products. But as it decreases the concentration of each species present by... |
Why is melting point of $\ce{Mg3N2}$ lower than that of $\ce{Be3N2}$ ?
I have two reasonings: <br>
1) The lattice energy of $\ce{Be3N2}$ is higher than that of $\ce{Mg3N2}$ so accordingly the melting point of the former should be higher <br>
2) Both of them form ionic nitrides. Since $\ce{Mg3N2}$ has more <b>ioni... |
$$\ce{NaCl + AgNO3 -> NaNO3 + AgCl (white colour)}$$
$$\ce{Na2CO3 + 2AgNO3 -> 2NaNO3 + Ag2CO3(brownish white colour)}$$
Generally $\ce{AgNO3}$ is used as confirmatory test of $\ce{Cl-}$ than if white precipitate is obtained then we should use method to remove carbonate from the solution before performing the abo... |
Distinction of chloride and carbonate anion is possible by silver nitrate or not? |
Why is the melting point of magnesium nitride less than that of beryllium nitride? |
> why is dH=dE at constant volume?
It isn't, and nowhere in the problem or answer is this implied.
First of all some definitions.
For a combustion reaction, the *enthalpy* change can be equated with the heat of combustion at constant pressure, whereas the *internal energy* is the heat of combustion at constan... |
In an equilibrium, why are partial pressures not affected by the coefficients of the balanced equation? |
#Books about Inorganic Chemistry
- **General texts**
- [Housecroft, C. E.; Sharpe, A. G. *Inorganic Chemistry*, 4th ed.; Prentice Hall: Upper Saddle River, NJ, 2012.](https://www.amazon.com/Inorganic-Chemistry-4th-Catherine-Housecroft/dp/0273742752)
- [Weller, M.; Overton, T.; Rourke, J.; Armstrong, F. *Inorgan... |
During the chirality analysis of various molecules containing rings, we assume for convenience that the rings are completely flat/planar and if the molecule has a plane of symmetry, it is achiral. However, does the fact that say, 6-membered rings actually exist in a chair or boat conformation have any effect on our fin... |
Does the 3D conformation of rings affect chirality? |
[![A reaction of organocadmium][1]][1]
In the above reaction, I was told that the reason organocadmium reacts only with aryl chloride segment is because it is very less reactive and reacts only with most reactive sites. This was consistent with my previous beliefs that **we always react most electrophilic and most n... |
When calculating the pH of methanoic/formic acid (HCOOH) why do we not multiply the given molarity of the acid by 2 as there are 2 moles of H+ ions, as seen in chemical formula HCOOH?
However when it comes to calculating the pH of sulfuric acid (H₂SO₄), we do multiply the given molarity by 2 as there are 2 moles of ... |
What is the product of the reaction of 2-methylbuta-1,3-diene (isoprene) with HBr?
[![2-methylbuta-1,3-diene][1]][1]
What I understand is that carbon (2) will get a positive charge after protonation.
But after this, which should be the major product?
- 3-bromo-3-methylbut-1-ene – because in this case the ca... |
What is the major product of the reaction of 2-methylbuta-1,3-diene with HBr? |
What happens if you add pure food grade lactic acid that is free of bacteria to fresh pasteurized milk? What chemical reactions would take place? What does it taste like straight after mixing and a short time later (not so much later that bacteria could multiply and sour the milk) Does it smell and taste like sour milk... |
I've heard that dioxygen difluoride (a.k.a FOOF) would set fire or react with nearly everything including sand ,bricks or even ice. Is this true? |
Will dioxygen difluoride set fire to sand? |
I was doing research on nuclear reactors and was wondering when the steam from the fission pushes the steam turbine does it do work on the system or to the system? |
Does steam from nuclear reactor does work on the system or to the system? |
**It is hard to be sure as it is too reactive to test**
FOOF has been made, though no sane person would want to repeat the most recent synthesis (see [the paywalled article reporting it][1]) as it involves passing oxygen a fluorine through a red hot metal tube. An [earlier paper that tested its reactivity][2] stored... |
If we consider adiabatic reactor (one which doesn't exchange energy and matter with surroundings) with some reaction in liquid phase, energy balance for such reactor is written as heat of reaction being equal to time derivative of enthalpy at any point in time. Since reaction is in liquid phase during reaction there ar... |
Can more than 1 mol of gas dissolve in 1 mol of H2O? |
$$\ce{NaCl + AgNO3 -> NaNO3 + AgCl (white colour)}$$
$$\ce{Na2CO3 + 2AgNO3 -> 2NaNO3 + Ag2CO3(brownish white colour)}$$
Generally $\ce{AgNO3}$ is used as confirmatory test of $\ce{Cl-}$ than if white precipitate is obtained then we should use method to remove carbonate from the solution before performing the abo... |
$$\ce{NaCl + AgNO3 -> NaNO3 + AgCl (white colour)}$$
$$\ce{Na2CO3 + 2AgNO3 -> 2NaNO3 + Ag2CO3(brownish white colour)}$$
Generally $\ce{AgNO3}$ is used as confirmatory test of $\ce{Cl-}$ than if white precipitate is obtained then we should use method to remove carbonate from the solution before performing the abo... |
$$\ce{NaCl + AgNO3 -> NaNO3 + AgCl (white colour)}$$
$$\ce{Na2CO3 + 2AgNO3 -> 2NaNO3 + Ag2CO3(brownish white colour)}$$
Generally $\ce{AgNO3}$ is used as confirmatory test of $\ce{Cl-}$ . Now if white precipitate is obtained on adding silver nitrate in original solution, then shall we use method to remove carbon... |
Suppose, we are given a solution containing two salts, one is a chloride salt and other one is a carbonate salt. Generally $\ce{AgNO3}$ is used as confirmatory test of $\ce{Cl-}$ (white precipitate is obtained on adding silver nitrate to solution containing the chloride salt). So, can we use this method to remove/disti... |
The order I was provided with is(comparing molecules of similar molecular mass from each);
alkanes< ethers< esters< aldehydes< ketones<< alcohols<< carboxylic acids<< amides
Where << is supposed to signify a considerable hike.
1) Here, how do you compare esters and ethers?
2) I assume the higher position of... |
Can we use silver nitrate to distinguish chloride and carbonate anion? |
I have this exact bottle: https://www.grasscity.eu/media/catalog/product/cache/2b55fa971a29a7844993ad77b24950ac/i/m/img_3633_1_1.jpg
I originally purchased it to clean my vaporizer (I've since stopped doing that and thrown all the equipment away), and now I'm wondering if this liquid is "isopropyl alcohol", because ... |
Is my bottle of "RooR"-brand glass cleaning liquid pure isopropyl alcohol or something else? |
On page 130 of Organic Chemistry by Clayden, it is stated that
"*Nucleophilic attack by the hydride ion, H−
, is an almost unknown reaction. This species,
which is present in the salt sodium hydride, NaH, has such a high charge density that it only
ever reacts as a base. The reason is that its fi lled 1s orbit... |
On page 130 of Organic Chemistry by Clayden, it is stated that
> Nucleophilic attack by the hydride ion, $\ce{H-}$, is an almost unknown reaction. This species, which is present in the salt sodium hydride, NaH, has such a high charge density that it only ever reacts as a base. The reason is that its filled 1s orbit... |
From [Khan Academy][1] starting from 1:25, the narrator, while talking about the Electrochemical gradients, said that sodium ions would naturally want to diffuse
down when having a high concentration up here and a low concentration down there.
My question is Why would sodium ions want to go down just because of on... |
Suppose, we are given a solution containing two salts, one may be a chloride salt and other one may be a carbonate salt (we need to identify the salts and we do not know the salts initially). Generally $\ce{AgNO3}$ is used as confirmatory test of $\ce{Cl-}$ (white precipitate is obtained on adding silver nitrate to sol... |
Can we use silver nitrate to distinguish between chloride and carbonate salts? |
I encountered the following question in an organic chemistry paper -
[![enter image description here][1]][1]
The reaction follows benzyne mechanism. My answer was A.
However, the answer given in the test solutions was D. The mechanism given was this -
[![enter image description here][2]][2]
[1]: https... |
Which side's hydrogen is removed during benzyne formation in substituted haloarenes? |
Initially, we are given a solution containing two salts, they can be either carbonate or chloride salts (we do not know their composition initially).
Generally, $\ce{AgNO3}$ is used as a confirmatory test of $\ce{Cl-}$ (a white precipitate is obtained on adding silver nitrate to solution containing the chloride salt... |
In statistical thermodynamics ,the quantity omega potential is defined and is different for fermions ,photons and phonons and other particles. I have been understanding the derivations of omega potential for varied particles but I feel I am not really able to physically interpret what exactly is omega potential? Is it ... |
If we consider adiabatic reactor (one which doesn't exchange energy and matter with surroundings) with some reaction in liquid phase, energy balance for such reactor is written as heat of reaction being equal to time derivative of enthalpy at any point in time. Since reaction is in liquid phase during reaction there ar... |
I am trying to repeat an experiment conducted by FDA on Malachite Green (MG).
According to [this paper][2],
Prepare a series of LC calibrants by aliquoting into individual 15 mL graduated
glass or disposable polypropylene centrifuge tubes, 50 µL, 100 µL, and 200 µL
of the 0.1 µg/mL MG2 solution a... |
The question requires me to identify the decreasing order of the acidic strength of the following functional group. But I'm afraid I don't know how to distinguish one from the other since all the hydroxyl groups would be in resonance. What would be the next step in this case? I felt like the answer should start with (i... |
How to go about deciding the acidic strength of a functional group in an aromatic compound? |
In statistical thermodynamics, the quantity omega potential is defined and is different for fermions, photons, phonons and other particles.
I have been understanding the derivations of omega potential for varied particles but I feel I am not really able to physically interpret what it actually is.
Is it similar... |
I was wondering in this problem that if chlorine will show positive mesomeric effect as it is at para position and strength of inductive effect decreases with distance from carbon atom and chlorine can expand its octet due to presence of d orbitals so will this structure be more stable than toluene carbocation i maen i... |
Can chlorine show negative mesomeric effect due to presence of d orbital? |
On page 130 of Organic Chemistry by Clayden, it is stated that
> Nucleophilic attack by the hydride ion, $\ce{H-}$, is an almost unknown reaction. This species, which is present in the salt sodium hydride, NaH, has such a high charge density that it only ever reacts as a base. The reason is that its filled 1s orbit... |
Short answer -
The OMe stabilises the negative charge in the *ortho* position
From Master Organic Chemistry.com [here][1] see *Case#2* below
> So how do substituents on the ring affect addition to the triple bond?
Since the aromatic pi-system is at right angles to the triple bond, what’s NOT relev... |
What is the crystal structure of Ammonium hydrogen sulfate? Its beautifully birefringent |
I was wondering in this problem that if chlorine will show positive mesomeric effect as it is at *para*-position and strength of inductive effect decreases with distance from carbon atom and chlorine can expand its octet due to presence of $\mathrm{d}$ orbitals so will this structure be more stable than toluene carboca... |
I am making an analog front end for a pH probe and i encountered a design where creating an offset on the reference electrode, creates an offset on the measure electrode.
How does that work ? Does the charge go through water ?
Experience based on TI application notes : https://www.ti.com/lit/an/snoa529a/snoa529a... |
Why does a potential on the reference electrode create an offset on the measure electrode of a pH probe? |
I am making an analog front end for a pH probe and i encountered a design where creating an offset on the reference electrode, creates an offset on the measure electrode.
How does that work ? Does the charge go through water ?
Experience based on TI application notes : https://www.ti.com/lit/an/snoa529a/snoa529a... |
We all know about potential energy curve of two H atoms v/s internuclear distance.[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/u9WPR.png
My teacher told me about the following curve that system with lowest potential energy is most stable therefore two H atoms are stable as a molecul... |
The [Morse potential](https://en.wikipedia.org/wiki/Morse_potential) can be used to describe the potential energy of the a diatomic bond:
<img src="https://i.stack.imgur.com/u9WPR.png" width="400" alt="Morse potential">
This curve suggests that the lowest state $v = 0$ is the most stable, since it has the lowest ... |
How is kinetic energy accounted for when describing diatomic bonds with a Morse potential? |
I encountered the following question in an organic chemistry paper -
[![enter image description here][1]][1]
The reaction follows benzyne mechanism. My answer was B.
However, the answer given in the test solutions was D. The mechanism given was this -
[![enter image description here][2]][2]
[1]: https... |
what type of forces exist between ions in molten ionic solids?
if this force is electrostatic attraction only then how is it different from electrostatic interaction when ionic compound exist as solid? |
You may find public records about the crystal structure of ammonium hydrogensulfate, $\ce{(NH4)3H(SO4)2}$, in the inorganic crystal structure database, ICSD, [here](https://www.ccdc.cam.ac.uk/structures/Search?Doi=10.1107%2FS0108768108041876&DatabaseToSearch=Published) with entries ISCD173738 and ISCD173739, which are ... |
When we talk about an unstable atom that will decay by emitting $\alpha$, $\beta$ or $\gamma$ radiation, the nucleus is the thing that's unstable, right?
As [Wikipedia](http://en.wikipedia.org/wiki/Beta_particle) puts it,
> An unstable atomic nucleus with an excess of neutrons may undergo β− decay, where a neutro... |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/QIguB.jpg
The picture above is from my class notes. I am familiar with the mechanism of both acid and base catalysed Aldol condensation. I also understand the reason why KCP was told as the major product in base catalysed Aldol condensation.... |
Why are we not getting the most stable product in Aldol condensation? |
[![slide notes][1]][1]
I was reviewing Dave Evans' notes for stereochemistry of C=X electrophile additions, and found this slide detailing differences in additions to cyclic oxo-carbenium electrophiles, but I don't understand why this selectivity is seen. With the OBn group, I can see that adding on the same face as t... |
How do electrostatic effects effect facial selectivity in addition to cyclic oxo-carbeniums? |
**Short answer:** The $\ce{OMe}$ stabilizes the negative charge in the *ortho* position
From Master Organic Chemistry.com [here][1] see *Case#2* below
> So how do substituents on the ring affect addition to the triple bond?
Since the aromatic pi-system is at right angles to the triple bond, what’s NOT rele... |
Brownian motion abounds in nature, but so does drift current. In theoretical models of solutions and colloidal suspensions it is sometimes assumed that advection is negligible. I'm wondering if this is a natural assumption to make, or if it is generally better (e.g. more informative, whether in a positive or negative... |
When is it realistic to model diffusion without advection? |
I've heard that dioxygen difluoride (a.k.a FOOF) would set fire or react with nearly everything including sand ,bricks or even ice. Is this true? |
Will dioxygen difluoride set fire to sand? |
Why is the electron configuration of Co+= [Ar]3d8?
The one of Co is [Ar]4s2 3d7
Wouldn't the electron be emitted from the s orbital and then wouldn't the electron configuration of Co+ be: [Ar]4s1 3d7?
What have I overlooked? Is there a rule that I have ignored? |
Why is the electron configuration of Co+= [Ar]3d8? |
The $\ce{pK_a}$ values of benzoic acid and phenylacetic acid are around 4.2 and 4.31 respectively.
In benzoic acid, you have the resonance being the dominating effect, destabilizing a conjugate base anion. In phenylacetic acid, resonance doesn't work anymore, and only the -I inductive effect remains, which should st... |
How to apply the Fajans rule?
I do not understand how to weigh the criteria cation, anion size and the cation charge.
At what point is the positive charge large enough? What if the criteria are contradictory, e.g. a large positive charge, large cation but small anion? Why is SnCl4 a molecule and SnCl2 a salt (is a 2 ... |
How to apply the Fajans rule? |
How to apply the Fajans rule?
I do not understand how to weigh the criteria cation, anion size and the cation charge.
At what point is the positive charge large enough? What if the criteria are contradictory, e.g. a large positive charge, large cation but small anion? Why is SnCl4 a molecule and SnCl2 a salt (is a 2 ... |
Generally, a *complete* orbital is energetically favored over an *incomplete*. [Ar]4s1 3d7 has *two* incomplete orbitals, *s* and *d*. Note also that the 4s orbital, though of a *higher* shell, is written *before* the 3d orbital, again, because it fills *before* *3d*.
[Ar]3d8 has *no* incomplete orbital, at the expe... |
Outside of bonds between metal atoms=metallic bonds, non-metals=covalent bonds (molecules), it is difficult for me to determine what kind of bond it is.
I know that in the rule metals and nonmetals form ionic bonds and that the ionic part of such bonds increases with increasing electronegativity difference and that Fa... |
Why is the electron configuration of $\ce{Co^+}$ $[\ce{Ar}](\mathrm{3d})^8$?
Since neutral $\ce{Co}$ itself has a $[\ce{Ar}](\mathrm{4s})^2(\mathrm{3d})^7$ configuration, wouldn't the ionised electron be lost from the $\mathrm{4s}$ orbital, leading to an electron configuration of $[\ce{Ar}](\mathrm{4s})^1(\mathrm{3d... |
Why does Co(I) have a 3d8 configuration? |
Generally, a *complete* orbital is energetically favored over an *incomplete*. [Ar]4s1 3d7 has *two* incomplete orbitals, *s* and *d*. Note also that the 4s orbital, though of a *higher* shell, is written *before* the 3d orbital, again, because it fills *before* *3d*.
[Ar]3d8 has *no* incomplete orbital, at the expe... |
Generally, a *complete* orbital is energetically favored over an *incomplete*. $\ce{[Ar]}4\mathrm s^1\,3\mathrm d^7$ has *two* incomplete orbitals, $\mathrm s$ and $\mathrm d$. Note also that the $4\mathrm s$ orbital, though of a *higher* shell, is written *before* the $3\mathrm d$ orbital, again, because it fills *bef... |
What is the crystal structure of ammonium hydrogen sulfate? It's beautifully birefringent |
I encountered the following question in an organic chemistry paper -
[![Multiple choice question on nucleophilic substitution through benzyne][1]][1]
The reaction follows benzyne mechanism. My answer was B.
However, the answer given in the test solutions was D. The mechanism given was as follows:
[![The me... |
Brownian motion abounds in nature, but so does drift current. In theoretical models of solutions and colloidal suspensions it is sometimes assumed that advection is negligible. I'm wondering if this is a natural assumption to make, or if it is generally better (e.g. more informative, whether in a positive or negative... |
Apparently the yield of alkyl chlorides is low as compared to that of alkyl bromides when preparing alkyl halides using the Hunsdiecker reaction.
Why does this occur? The only factor I can see is the lower stability of the free radical of chlorine as compared to that of bromine, as the reaction proceeds by the free-... |
I encountered the following question in an organic chemistry paper -
[![Multiple choice question on nucleophilic substitution through benzyne][1]][1]
The reaction follows benzyne mechanism. My answer was B.
However, the answer given in the test solutions was D. The mechanism given was as follows:
[![The me... |
What class of compounds does this belong to, if it exists; $$\ce{CH3-CH2-CN-CH3}$$
I honestly don't know if it exists; it popped up in my head while I was reading up on nitrile compounds, and I haven't heard of this type of molecule, thus the question.
If it doesn't exist, why not? |
The mechanisms for both acid and base catalyzed hydrolysis of nitriles are clear;
[![enter image description here][1]][1]
(With the subsequent deprotonation from the hydroxyl) and
[![enter image description here][2]][2]
([Source][3])
[1]: https://i.stack.imgur.com/fXyEJ.png
[2]: https://i.stac... |
Cyanide hydrolysis; could it yield an oxime? |
When water is heated, the molecules of the water gain energy which leads to dissociation of water molecules. Does this means that pH of water has changed? |
I checked some articles, including [*Hydrometallurgy ***2012***, 133-144, 185-191*][1] and [*Hydrometallurgy **2000**, 57, 269-275*][2]. In all research papers I checked, an exothermic stripping process followed an endothermic solvent extraction process and vise versa. First, what reasons can be behind such phenomena? ... |
If a metal's solvent extraction process is exothermic, then the stripping is necessarily endothermic? |
This is a question I don't understand in thermo. Enthalpy of compound would be sum of U + PV at some temperature, but since we can't calculate absolute value of H, we calculate it relatively to some reference. Enthalpy of formation is heat needed to be exchanged between system and surroundings at some pressure to keep ... |
Why is Enthalpy of Compound at Some Temperature Equal to its Enthalpy of Formation at the Same Temperature? |
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