instruction stringlengths 15 21.8k |
|---|
I was given the following question on a sample exam for my organic chemistry course:
>![reaction][2]
I am quite certain that it would happen in a S<sub>N</sub>2-type reaction considering that
1. the nucleophile is $\ce{CN-};$
2. the solvent is DMF.
However, I'm not sure what electrophilic center would be a... |
The three more energy electron layers for Indium(49) are, sorted from lower to higher energy:
[Kr] $5\text{s}^24\text{d}^{10}5\text{p}^1$
From this configuration, it could be said that is easy to subtract the $5\text{p}^1$ electron (oxidation state +1), next start subtracting electrons from the 4d layer. However,... |
When electrons are removed from an atom, those in the **outermost** orbital is removed first. The p orbitals are most away from the nucleus, then the s orbitals, and finally the d orbitals. In fact, the closeness of d orbitals to the nucleus accounts for higher energy of the 4d orbitals than the 5s orbital. Because ele... |
I'm simulating using a CFD solver a pure oxygen/methane flame. However, I doubt that the combustion model does not produce enough heat. The heat from reaction is defined by $S_h=-\sum_{j} \frac{h_j^0}{M_j}R_j $ with $h_f^0[J/kg]$ the enthalpy of formation, M$_j$ the molar mass and $R_j$ the reaction rate of species $j$... |
I'm simulating using a CFD solver a pure oxygen/methane flame. However, I doubt that the combustion model does not produce enough heat. The heat from reaction is defined by $S_h=-\sum_{j} \frac{h_j^0}{M_j}R_j $ with $h_f^0[J/kgmol]$ the enthalpy of formation, M$_j$ the molar mass and $R_j$ the reaction rate of species ... |
I need some help understanding the hypervalent iodine phenolic coupling reaction taking place in this synthesis of morphine, the reaction uses PhI(OAc)2 as the hypervalent reagent and trifluoroethanol as a solvent.
[![enter image description here][1]][1]
1) What is the mechanism taking place here? From my under... |
I need some help understanding the hypervalent iodine phenolic coupling reaction taking place in this synthesis of morphine, the reaction uses PhI(OAc)2 as the hypervalent reagent and trifluoroethanol as a solvent.
[![enter image description here][1]][1]
1) What is the mechanism taking place here? From my under... |
I need some help understanding the hypervalent iodine phenolic coupling reaction taking place in this synthesis of morphine, the reaction uses $\ce{PhI(OAc)2}$ as the hypervalent reagent and trifluoroethanol as a solvent.
[![enter image description here][1]][1]
1) What is the mechanism taking place here? From my ... |
The wavelength has to be comparable with the object size in order to see those effects. Your macroscopic hand will *not* rotate ordinary light even if you have millions hands around, because the wavelength of light is so small. Yes, it will scatter light as a large object. This idea of optical rotation by long waveleng... |
> Please explain using plain english (without any rules or tables) why is that in asymmetric stretching like the following, there is no change in the size, shape or orientation of the electron cloud that surrounds the molecule?
**There is a change.** The size and shape of the electron cloud does change for the indi... |
The "structures" you are trying to post and their respective names do not match, as I cannot spot a phenyl group in there. (Also it is hard to tell from this diagram.) But based on what you gave us, I believe these are the same compounds, where ethyl 10-(4-iodophenyl)undecanoate is the correct IUPAC name and Ethyl iodo... |
>[OP] the average kinetic energy of evaporating water molecules
You have to specify whether you are talking about the kinetic energy just before the water molecule breaks the hydrogen bonds to its neighbors or just afterwards. A millisecond before or after the event, of course, the average kinetic energy will be det... |
>[OP] the average kinetic energy of evaporating water molecules
You have to specify whether you are talking about the kinetic energy just before the water molecule breaks the hydrogen bonds to its neighbors or just afterwards. A millisecond before or after the event, of course, the average kinetic energy will be det... |
Suggest one reason why HCl has only one peak?
Does this have something to do with fact that peaks (in IR spectroscopy) represent areas of the spectrum where specific bond vibrations occur and therefore since HCl has a single bond it only has one peak to show only one bond vibration
I don't know if I explained thi... |
Why does the infrared spectrum of HCl only have one peak? |
There are different types of lattices. A lattice point is a point in any of these lattices. Lattices are used to describe highly ordered systems such as crystals and some [supersolids][1]. I am unsure whether lattices can only describe periodic systems (see [quasicrystals][2]). However, I will be assuming that we are ... |
Suggest one reason why HCl has only one peak?
Does this have something to do with fact that peaks (in IR spectroscopy) represent areas of the spectrum where specific bond vibrations occur and therefore since HCl has a single bond it only has one peak to show only one bond vibration? |
I am an industrial electrician apprentice who needs to learn more about pH-measurements and how the temperature effects the measurement itself (I am in charge of all the pH measurements on the powerplant I work at and I have no one to ask about this stuff as no one knows a thing about pH measurements).
So far I have... |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/iZIqK.jpg
I have been told by my instructors that for aromaticity it is necessary for the molecule to be planar, but in the given molecule Oxygen seems to be out of the plane of the conjugated system, so my question is why is this molecule... |
In [this][1] answer, I don't understand how this step worked.
> Using $\mu_i = \mu^\circ_i + RT\ln \frac{P_i}{\pu{1 bar}}$
\begin{align}
\Delta G &= (c\mu^\circ_\ce{C} + d\mu^\circ_\ce{D} - a\mu^\circ_\ce{A} - b\mu^\circ_\ce{B}) + RT \ln\frac{P_\ce{C}^c P_\ce{D}^d}{P_\ce{A}^a P_\ce{B}^b}\\
\Delta G &= \Delta G^\c... |
How are these three things equal? |
Do all chiral objects rotate the plane of polarization of EM waves? For example my hand is chiral, will it rotate the plane of polarization of EM waves of suitable wavelength? |
The ammonium cation, as well as well as the dihydrogen anion, is a weak acid.
I have a weak solution of this salt, $C_A\approx 0.05\mathbf{M}$, that I need to quantitatively determine.
My first thought was acid-base titration because it's cheap and easy but the presence of two weak acids complicates things.
Wo... |
In the the compound RCONH2 which lone pair is more basic? Is it the lone pairs on Oxygen atom or the lone pair on Nitrogen atom.
I believe that as O is more electronegative than N, the lone pair on O is of lower energy. Hence, the O's lone pairs are less basic. (But if one draws the resonance structure for the comp... |
Identifying which lone pair is more basic? |
> Why is nitrous acid prepared *in situ*?
I am not sure about the above question. First of all, I don't exactly understand what is meant by "*in situ*". Secondly, how would preparing nitrous acid *in situ*, in the diazotisation of amines with nitrous acid, make it less toxic or unstable? |
Acid-Base Titration of ammonium dihydrogenphosphate? |
How can I determine the concentration of ammonium dihydrogenphosphate solution?
In this compound, the ammonium cation and the dihydrogen anion are both weak acids.
I have a weak solution of this salt, $C_A\approx 0.05\mathbf{M}$, that I need to quantitatively determine.
My first thought was acid-base titration... |
Strong acid pH increases by one unit when diluted by a factor of 10, but why do weak acids not? |
Why does the pH of a weak acid not increase by 1 when diluted by a factor of 10? |
I presume the role is to soak up the HI that is formed. Why not other bases such as triethylamine? Is this because the quaternary ammonium salt could be formed? Would other non-nucleophilic or inorganic bases work (for instance, k2co3 or DBU)?
http://www.commonorganicchemistry.com/Rxn_Pages/Alcohol_to_Halide/Iodide/... |
What is the role of imidazole in the Appel Reaction with iodine (I2)? Why are other bases not used? |
Parathion itself has been found to be a very weak inhibitor of acetylcholinesterase. It normally requires metabolic activation and the conversion into paraoxon in the body to actually start exhibiting anticholinesterase activity. However, the study cited below found that active isomers of parathion, O,S-Diethyl O-4-nit... |
Why are isomers of parathion less active acetylcholinesterase inhibitors than paraoxon? |
Parathion itself has been found to be a very weak inhibitor of acetylcholinesterase. It normally requires metabolic activation and the conversion into paraoxon in the body to actually start exhibiting anticholinesterase activity. However, the study cited below found that active isomers of parathion, O,S-Diethyl O-4-nit... |
From [wiki page][1] about valence electrons:
> An atom with a closed shell of valence electrons (corresponding to an
> electron configuration $s^2p^6$ for main group elements or $d^{10}s^2p^6$ for
> transition metals) tends to be chemically inert.
My question is, which are the transition metals with $d^{10}s^... |
The zinc atom $\ce{Zn}$ has the configuration $\ce{(Ar) 3d^{10} 4s^2}$ or, if you prefer : $\ce{1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 }$. The same final configuration is repeated with the cadmium atom $\ce{Cd}$, and with the mercury atom $\ce{Hg}$. Is it not what you are looking for ? |
$$\ce{SiO2 + C -> Si + CO2}$$
Does this mean C is more reactive than Si? But Si is more electropositive than C.
What is the explanation for this? |
>Why does a solution become less temperature dependent the more acidic it is? Basic solutions are extremely temperature sensitive, neutral solution still significant sensitive, but highly acidic solutions don't seem give a damn about temperature. Why is that?
Is this statement based on theory or on your own experien... |
What is the role of red phosphorus in hvz reaction?
Initially I think that red phosphurus is nothing but a catalyst. But it is not a catalyst. |
$$\ce{SiO2 + C ->[2200°C] Si + CO2}$$
Does this mean C is more reactive than Si? But Si is more electropositive than C.
What is the explanation for this? |
$$\ce{SiO2 + C ->[2200°C] Si + CO2}$$([Ref](https://en.m.wikipedia.org/wiki/Silicon#Production))
Does this reaction mean C is more reactive than Si? But Si is more electropositive than C.
What is the explanation for this? |
**TL;DR:** When $\ce{PBr3/PCl3}$ is not available as reagent, red phosphorus is used which is reacted to bromine or chlorine to form the reagents *in situ*.
**Long answer:**
Hell–Volhard–Zelinsky halogenation reaction halogenates carboxylic acids at the α-carbon. The reaction is initiated by addition of a cataly... |
With the help of HVZ reaction, we can get alpha-chloro or alpha-bromo carboxylic acid.
[![enter image description here][1]][1]
But can we make alpha-iodocarboxylic acid with the help of HVZ reaction? I could not find any reference of HVZ reaction forming alpha-iodocarboxylic acid.
Though $\ce{PI3}$ is much les... |
Can we use PI3 in HVZ reaction? |
$$\ce{SiO2 + 2C ->[2200°C] Si + 2CO}$$([Ref](https://en.m.wikipedia.org/wiki/Silicon#Production))
Does this reaction mean C is more reactive than Si? But Si is more electropositive than C.
What is the explanation for this? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/wMziy.png
I don’t understand why the conductivity doesn’t change after the equivalence point. To my understanding, at the equivalence point there is NH3, NH4+ and Cl- in the solution. As more NH3 is added it only partially dissociates, t... |
**TL;DR:** When $\ce{PBr3/PCl3}$ is not available as reagent, red phosphorus is used which is reacted to bromine or chlorine to form the reagents *in situ*.
**Long answer:**
Hell–Volhard–Zelinsky halogenation reaction halogenates carboxylic acids at the α-carbon. The reaction is initiated by addition of a cataly... |
My question is simple, Can an isotope have a charge? i.e the number of neutrons and electrons defer in that atom.
If it does exists, Is it right to call it an Ion Isotope? (or Isotope Ion)
Thanks in advance. |
For a first-order phase transition such as water to steam , we write [Clausius-Clapeyron equation][1] as:
$\frac{dP}{dT}= \frac{L}{T \Delta V}$
Now what I infer from this equation is that if the phase-transition takes place at a lower T (that is boiling point is lower) then the rate on the LHS increases which ba... |
For a first-order phase transition such as water to steam , we write [Clausius-Clapeyron equation][1] as:
$\frac{dP}{dT}= \frac{L}{T \Delta V}$
Now what I infer from this equation is that if the phase-transition takes place at a lower T (that is boiling point is lower) then the rate on the Left Hand Side increas... |
Can an isotope have a charge, i.e. the number of neutrons and electrons differ in that atom?
If it does exists, is it correct to call it an *ion isotope* or *isotope ion*? |
Can an ion isotope exist? |
From [wiki page][1] about valence electrons:
> An atom with a closed shell of valence electrons (corresponding to an
> electron configuration $s^2p^6$ for main group elements or $d^{10}s^2p^6$ for
> transition metals) tends to be chemically inert.
My question is, which are the transition metals with $d^{10}s^... |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/wMziy.png
I don’t understand why the conductivity doesn’t change after the equivalence point. To my understanding, at the equivalence point there is $\ce{NH3}$, $\ce{NH4+}$ and $\ce{Cl-}$ in the solution. As more $\ce{NH3}$ is added it o... |
Recently, at my place, a sort of filter for hard water was installed. They told me that it contains sodium triphosphate which is dissolved into all the water that enter home, i.e. both cold and hot water to prevent calcium carbonate to accumulate into the plumbing system, dishwasher, etc.... From what I can understand,... |
What about sodium triphosphate in drinking water? |
>Why does a solution become less temperature dependent the more acidic it is? Basic solutions are extremely temperature sensitive, neutral solution still significant sensitive, but highly acidic solutions don't seem give a damn about temperature. Why is that?
Is this statement based on theory or on your own experien... |
Recently, at my place, a sort of filter for hard water was installed. They told me that it contains sodium triphosphate which is dissolved into all the water that enter home, i.e. both cold and hot water to prevent calcium carbonate to accumulate into the plumbing system, dishwasher, etc.... From what I can understand,... |
$$\ce{SiO2 + 2C ->[2200°C] Si + 2CO}$$([Ref](https://en.m.wikipedia.org/wiki/Silicon#Production))
Does this reaction mean C is more reactive than Si? But Si is more electropositive than C.
What is the explanation for this? Where will Si be placed in the reactivity series? |
$$\ce{SiO2 + 2C ->[2200°C] Si + 2CO}$$([Ref](https://en.m.wikipedia.org/wiki/Silicon#Production))
In this reaction, C is [displacing][1] Si from SiO2. Does this mean C is more reactive than Si? But Si is more electropositive than C. What is the explanation for this? Where will Si be placed in the reactivity series?
... |
Recently, at my place, a sort of filter for hard water was installed. They told me that it contains sodium triphosphate which is dissolved into all the water that enter home, i.e. both cold and hot water to prevent calcium carbonate to accumulate into the plumbing system, dishwasher, etc.... From what I can understand,... |
According to the Arrhenius equation the rate of a reaction increases as at higher temperature a greater percentage of molecules have **translational** kinetic energy greater than or equal to activation energy [Wikipedia][1].
[1]: https://en.wikipedia.org/wiki/Activation_energy
I was recently introduced in molec... |
$$\ce{SiO2 + 2C ->[2200°C] Si + 2CO}$$([Ref](https://en.m.wikipedia.org/wiki/Silicon#Production))
In this reaction, C is apparently [displacing][1] Si from SiO2. Does this mean C is more reactive than Si? But Si is more electropositive than C. What is the explanation for this? Where will Si be placed in the reactivity... |
Recently, at my place, a sort of filter for hard water was installed. They told me that it contains sodium triphosphate which is dissolved into all the water that enter home, i.e. both cold and hot water to prevent calcium carbonate to accumulate into the plumbing system, dishwasher, etc.... From what I can understand,... |
I'm don't know the english terminology for chemistry so sorry for probably butchering some terms.
My question is, which of these is more reactive in an E1 reaction:
[![E1 reaction][1]][1]
The bottom two are the intermediates.
To determine the most reactive molecule, we look at the most stable intermediate.
... |
This depends upon the theory used to model the reaction; there are two major ones.
**Collision Theory**
If your molecules may be assumed to be spherical particles with no rotational or vibrational DOF, then collision theory appropriately describes your system. In this case, only translational energy is accounted ... |
This depends upon the theory used to model the reaction; there are two major ones.
**Collision Theory**
If your molecules may be assumed to be spherical particles with no rotational or vibrational DOF, then collision theory appropriately describes your system. In this case, only translational energy is accounted ... |
This depends upon the theory used to model the reaction; there are two major ones.
**Collision Theory**
If your molecules may be assumed to be spherical particles with no rotational or vibrational DOF, then collision theory appropriately describes your system. In this case, only translational energy is accounted ... |
This depends upon the theory used to model the reaction; there are two major ones.
**Collision Theory**
If your molecules may be assumed to be spherical particles with no rotational or vibrational DOF, then collision theory appropriately describes your system. In this case, only translational energy is accounted ... |
How is this compound aromatic? |
How is 4H‐1,4‐oxazocine aromatic? |
This depends upon the theory used to model the reaction; there are two major ones.
**Collision Theory**
If your molecules may be assumed to be spherical particles with no rotational or vibrational DOF, then collision theory appropriately describes your system. In this case, only translational energy is accounted ... |
This depends upon the theory used to model the reaction; there are two major ones.
**Collision Theory**
If your molecules may be assumed to be spherical particles with no rotational or vibrational DOF, then collision theory appropriately describes your system. In this case, only translational energy is accounted ... |
After reading one of the latest findings by scientists, Stardust was considered the oldest material on earth. However having not much of an experience with chemistry, I was intrigued upon how scientists were able to find such finding therefore from my understanding, scientists used spectrometry to determine composition... |
How reliable is spectrometry in the determination of the oldest material Startdust? |
Would the initial step of this mechanism be exothermic or endothermic? (Protonation) |
I need a broad-spectrum antifungal (yeast and mold) agent for an aqueous non-food product (pH ~6) that contains 20% v/v alcohol (ethanol or isopropanol). I would prefer it to be a food-grade preservative—or, barring that, something not on the California Prop. 65 list. What preservative (or combination of preservati... |
Food-grade antifungal preservatives for alcohol-containing aqueous non-food product that won't UV-yellow when dried? |
I need a broad-spectrum antifungal (yeast and mold) agent for an aqueous non-food product (pH $\simeq$ 6) that contains 20% v/v alcohol (ethanol or isopropanol). I would prefer it to be a food-grade preservative—or, barring that, something not on the California Prop. 65 list. What preservative (or combination of pr... |
In the synthesis of carboxylic acid derivatives (esters, amides), I often see N-hydroxysuccinimide used in conjunction with a coupling reagent (EDC, DCC). The reason given for this (from online) is that N-hydroxysuccinimide is a good leaving group.
Can anyone explain why this is so? I am unable to think of any reas... |
Consider continuous-wave EPR for species with only one unpaired electron in the following argument.
The interaction energy in the presence of external magnetic field of strength *B* is given by
$$E = Bg\mathrm{m_s}\mu_\mathrm{B} - Bg_{\mathrm{N}}\mathrm{m_I}\mu_\mathrm{N} + a\mathrm{m_sm_I}$$
Taking the specif... |
I need a broad-spectrum antifungal (yeast and mold) agent for an aqueous non-food product (pH $\simeq$ 6) that contains 20% v/v alcohol (ethanol or isopropanol). A key requirement is that it not UV-yellow if it comes into contact with textiles (e.g., clothing) after drying.
I would prefer it to be a food-grade pre... |
Recently, at my place, a sort of filter for hard water was installed. They told me that it contains sodium triphosphate which is dissolved into all the water that enter home, i.e. both cold and hot water to prevent calcium carbonate to accumulate into the plumbing system, dishwasher, etc.... From what I can understand,... |
The specific heat of water is lower than that of NH3, but why?
H20 forms more hydrogen bonds if I am right, besides there's more electronegativity for Oxygen
But still, NH3 has higher Specific heat. I found [this link][1] saying NH3 has lower molar mass, but its just by one gram so it shouldn't be having much eff... |
Why is Specific heat of Ammonia higher than water? |
The specific heat of water is lower than that of $\ce{NH3}$, but why?
$\ce{H2O}$ forms more hydrogen bonds if I am right, besides there's more electronegativity for Oxygen.
But still, $\ce{NH3}$ has higher Specific heat. I found [this link][1] saying $\ce{NH3}$ has lower molar mass, but its just by one gram so it... |
I tried to create a suspension of **EDTA powder in Glycerin with 1:1 ratio**. *I keep facing problem of EDTA sedimentation*. I've tried other ratios also but this was the only one which formed least amount of sediment.
When I used coarse powder, the sediment formed within 24 hours but when finely ground powder was u... |
EDTA sedimentation problem? |
Just to be clear, I do understand that the units of the rate constant *k* is selected to make the equation dimensionally consistent. That is not what I am asking.
It should be the case that *k* 'means' something physically, which is implied by its dimensions/units. And I would also assume that what *k* 'means' shoul... |
Why do the units of rate constants change, and what does that physically mean? |
Maybe it would make more sense if rate constants would have different symbols depending on whether it is a zero, first or second order reaction.
As an analogy, we might be asking "how big" an object is depending on the length of it. Depending whether the object is, say, a square, a cube or a hypercube, the answer wo... |
What is the proper use of the term "pi-donor ligand"? |
[![11-oxabicyclo(4.4.1)undeca-1,3,5,7,9-pentaene][1]][1]
I have been told by my instructors that for a compound to be aromatic, it must be planar. In this given molecule the oxygen seems to be out of the plane of the conjugated system: how can it still be aromatic, then?
[1]: https://i.stack.imgur.com/vYeY9.p... |
Why is 11-oxabicyclo(4.4.1)undeca-1,3,5,7,9-pentaene aromatic? |
The "sugar" you refer to is *sucrose*, which is a *disaccharide* (a fancy term we use for a type of sugar, composed of two *other* bits of sugar called *monosaccharides*; which in this case, are glucose and fructose). I felt I ought to have brought up the sucrose specification, since when you talk chemistry, "sugar" ca... |
We all know that when naming molecular compound, there is a rule that says no 2 vowels in a row. e.g. mono-oxide becomes monoxide.
What happen then, when we have di-iodine? From the google search, this is called diiodine everywhere, while seemingly it should be called diodine |
When naming compounds, sometimes when there are two vowels in a row the second is elided: this happens for example with "mono-oxide", which becomes "monoxide" instead.
Why is this not always applied, e.g. with "diiodine"? Why aren't the repeated i's removed to make it "diodine"? |
Why "monoxide" but not "diodine"? |
There are several Inconels , the basic one is 600. Because the Inco and Huntington divisions are now gone or acquired ,it would be difficult to get literature . But they produced copious amounts , you may be able to find some ; I have about a 6" stack of brochures I have been too lazy to discard. American Society for M... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.