instruction stringlengths 15 21.8k |
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What is the difference between the KLMN and SPDF methods of finding electronic configuration? |
I have a question regarding mol files.For example I have this molecule-
![enter image description here][1]
[1]: https://i.stack.imgur.com/KZYXH.png
The mol file for this is-
Sample
22 23 0 0 0 0 0 0 0 0999 V2000
-2.5962 2.2535 0.0000 C 0 0 0 0 0 0 0 0 0 ... |
I have a question regarding mol files.For example I have this molecule-
![enter image description here][1]
[1]: https://i.stack.imgur.com/KZYXHm.png
The mol file for this is-
Sample
22 23 0 0 0 0 0 0 0 0999 V2000
-2.5962 2.2535 0.0000 C 0 0 0 0 0 0 0 0 0... |
In his 1926 thesis Robert Cady Burts describes the production of sodium by electrolysis of sodium nitrate through glass:
http://thesis.library.caltech.edu/4369/1/Burt_rc_1926.pdf
I can't find much else on this method. Are there any modern descriptions of the experiment? Videos maybe? |
In his 1926 thesis Robert Cady Burts [describes the production of sodium by electrolysis of sodium nitrate through glass](http://thesis.library.caltech.edu/4369/1/Burt_rc_1926.pdf).
I can't find much else on this method. Are there any modern descriptions of the experiment? Videos maybe? |
> Air contain 20 % $\ce{O2}$ by volume. How many cm³ of air will be required
> for oxidation of 100 cm³ of acetylene?
>(a) 1064 cm³
(b) 212.8 cm³
(c) 500 cm³
(d) 1250 cm³
***Answer: (d)***
My solution:
**equation:** $$\ce{2C2H2 +5O2 -> 4CO2 +2H2O}$$
From stoichiometric calculations:
2 $\ce{... |
Air contain 20 % O2 by volume. How many cm³ of air will be required for oxidation of 100 cm³ of acetylene? |
What is the entropy change when the temperature of 1.00 mol of ideal gas is raised reversibly from 10 °C to 50 °C at constant pressure, constant volume, and assuming the heat capacity is independent of temperature?
This is all the information given. I am assuming that the formula $\Delta S = C \ln (T_2/T_1)$ is used... |
Can someone explain me why in this part of the reaction there is a rearrangement reaction of carbocation 1 to carboction 2 ? For me the second carbocation is less stable than the first which is more substituted...
![enter image description here][1]
Thank you in advance
[1]: https://i.stack.imgur.com/CVrEn... |
Can someone explain to me why there is a rearrangement reaction of carbocation 1 to carboction 2? To me the second carbocation appears to be less stable than the first because it is less substituted.
![enter image description here][1]
Thank you in advance
[1]: https://i.stack.imgur.com/CVrEn.png |
<a href="https://i.stack.imgur.com/yYuuh.jpg"><img src="https://i.stack.imgur.com/ovimO.png" title="source: imgur.com" /></a>
What would you have chosen as a mechanism?
Would $S_N1$ occur here?
I chose $S_N2$ because we have a secondary alkyl halide with a weak base $\ce{CN-}$.
However, the solution says $S_N... |
I used nail polish remover on an expensive phone case to remove sticker residue (and it worked, no longer sticky). I didn't know it didn't mix well with plastic materials. Did the acetone damage it? |
I understand that a polar solvent will help dissociate the $\ce{HBr}$ into ions.
But why a protic solvent?
Why would we want a solvent that would encage the $\ce{Br}$ and $\ce{H}$ ions?
Why is the aprotic not favored? My textbook does not discuss this and I searched online, with no result. |
> why a protic solvent?
Protic solvents tend to have higher dielectric constants than typical, **unreactive**, non-protic solvents. Look at the following table.
\begin{array}{|c|c|c|}\hline
solvent & dielectric~ constant \\ \hline
methanol & 32.6 \\ \hline
ethanol & 24.6 \\ \hline
methylene~chloride ... |
From EN alone we might expect $\ce{HCl}$ to be more polar but a book says that the bent structure of $\ce{H2S}$ gives rise to its polarity - which is also apparently more than $\ce{HCl}$. Why? Does this have to do with the lone pairs? Lone pairs supply electron density, right? |
How does carbonic acid cause acid rain when $K_b$ of bicarbonate is greater than $K_a$? Should it not create an alkaline solution?
$K_a = 4.8 \times 10^{-11}\ (mol/L)$. $K_b = 2.3 \times 10^{-8}\ (mol/L)$. These are the values for $\ce{HCO3-}$.
These numbers are from a school book that I read, but it's not in En... |
What is the ${K_a}$ of carbonic acid? Note that sources differ in their ${K_a}$ values, and especially for carbonic acid, since there are two kinds - a pseudo-carbonic acid/hydrated carbon dioxide and the real thing (which exists in equilibrium with hydrated carbon dioxide but in a small concentration - about 4% of wh... |
In cold countries, it is a common phenomena to add salt to melt or clear snow. However, only specific salts are being commercially. So my question is that why only sodium chloride and $\ce{CaCl2}$ are used for addition to snow, to melt/clear it? |
If there is no visual damage, e.g. cloudiness or crazing, the case should be OK. If there's some surface cloudiness, it might be possible to buff it out with mild abrasive, such as toothpaste or [milk of magnesia][1].
In the future, try oil (olive, safflower, mineral etc., but not motor oil) to remove stickers. A bi... |
Can someone explain to me why there is a rearrangement reaction of carbocation 1 to carbocation 2? To me the second carbocation appears to be less stable than the first because it is less substituted.
![enter image description here][1]
Thank you in advance
[1]: https://i.stack.imgur.com/CVrEn.png |
what is the difference between the terms 'solve' and 'dissolve'? up until now I have used the two terms interchangeably, not having any sound scientific definitions for each. I have thought them both to mean to make a solid into a solution through the addition of a solvent (not sure if only for solids into solutions, i... |
I had a quick question. I was doing a homework assignment and I got the following question wrong because I was supposed to multiply the empirical formula by 3 to get the molecular formula of C6H10S2O. I put (C6H10S2O3)3 and the teacher said it should be C18H30S6O3. My question is: isn't what I put the same thing? P... |
I was doing a homework assignment and I got the following question wrong because I was supposed to multiply the empirical formula by 3 to get the molecular formula of $\ce{C6H10S2O}$. I put $\ce{(C6H10S2O3)3}$ and the teacher said it should be $\ce{C18H30S6O3}$. My question is: isn't what I put the same thing? Pleas... |
what is the difference between the terms 'solve' and 'dissolve'? up until now I have used the two terms interchangeably, not having any sound scientific definitions for each. I have thought them both to mean to make a solid into a solution through the addition of a solvent (not sure if only for solids into solutions, i... |
Just curious. Does food coloring somehow evaporate and turn into nothing? Or does the beverage itself being much more color intensive?
I had a bottle of Gatorade, colored Lemon-Lime (and flavored as such). I noticed that after leaving the bottle in the car during a hot day and returned to the car, that condensatio... |
Why is condensation colorless? |
Given that the majority of beverages such as Gatorade is water, as stated in the comments, the condensate is predominantly water, as can be seen in the Patent [Electrolyte blends providing reduced salty taste][1] (which includes Gatorade), that water amounts to well over 99% by composition, of course this will vary.
... |
Given that the majority of beverages such as Gatorade is water, as stated in the comments, the condensate is predominantly water, as can be seen in the Patent [Electrolyte blends providing reduced salty taste][1] (which includes Gatorade), that water amounts to well over 99% by composition, of course this will vary. Th... |
Does food coloring somehow evaporate and turn into nothing? Or does the beverage itself being much more color intensive?
I had a bottle of Gatorade, colored Lemon-Lime (and flavored as such). I noticed that after leaving the bottle in the car during a hot day and returned to the car, that condensation had formed o... |
Why is condensation in dyed beverages colorless? |
Given that the majority of beverages such as Gatorade is water, as stated in the comments, the condensate is predominantly water, as can be seen in the Patent [Electrolyte blends providing reduced salty taste][1] (which includes Gatorade), that water amounts to well over 99% by composition, of course this will vary. Th... |
Is it possible to calculate energy of electron in any orbital and atom in schrodinger wave model theory? E.g. energy of 3s2 Electron of Na- ion. |
Is it possible to calculate energy of electron in any orbital and atom in schrodinger wave model theory? |
Is it possible to calculate the energy of electron in any orbital and atom in the Schrodinger Wave model theory? E.g. energy of the $3s^2$ electron of the $\ce{Na-}$ ion. |
Is it possible to calculate the energy of electron in any orbital and atom in the Schrodinger Wave model theory? If so, how? E.g. energy of the $3s^2$ electron of the $\ce{Na-}$ ion. |
I guess the ethyl group should be in the parent chain and the numbring should start from right. Hence, the compound should be named 2-methylhept-1-ene-1,3,4,5-tetracarbonitrile. Am I wrong somewhere![irga][1]?
[1]: https://i.stack.imgur.com/0IW6E.jpg |
Is the compound named correctly? |
Is NaCl in water aqueous? for certain amount of NaCl It can dissolve in water but if you add more NaCl it can't dissolve more ..
So, if in a certain reaction NaCl is formed with water:
HCl(Aq) + NaOH(Aq) --> H2O(L) + NaCl(Aq)
My question is does NaCl in the previous reaction totally dissolve in the water forme... |
Is NaCl in water considered "solution" despite of NaCl have some precepetation? |
What's the value of standard potential of carbon?
The hydrogen and Carbon are in the electrochemical series despite being non metals hydrogen has zero potential difference what about carbon? |
What is the standard potential of carbon? |
The epoxide on the top of the picture, in aqueous acid hydrolyzes to the compound below. What is the mechanism of this reactions? Standard epoxide opening in acidic conditions would happen at the more substituted end, therefore the secondary -OH group would end below the plane of the paper, and the other center would r... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/vUDVu.jpg
In the image that follows (7)
I believe that the first step is the Cannizzaro reaction which will give (c) as a product.
But since we are also adding H+ in the second step, shouldn't an esterification reaction take place? That ... |
Does esterification require reactants to be present in the same plane? |
The epoxide on the top of the picture, in aqueous acid hydrolyzes to the compound below. What is the mechanism of this reaction? Standard epoxide opening in acidic conditions would happen at the more substituted end, therefore the secondary -OH group would end up below the plane of the paper, and the tertiary center wo... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/vUDVu.jpg
In the image that follows (7)
I believe that the first step is the Cannizzaro reaction which will give (c) as a product.
But since we are also adding $\ce{H+}$ in the second step, shouldn't an esterification reaction take place... |
Is $\ce{NaCl}$ in water aqueous? For a certain amount of $\ce{NaCl}$, it can dissolve in water but if you add more $\ce{NaCl}$ it can't dissolve any more.
So, if in a certain reaction $\ce{NaCl}$ is formed with water:
$$\ce{HCl(aq) + NaOH(aq) -> H2O(l) + NaCl(aq)}$$
My question is does $\ce{NaCl}$ in the previ... |
While naming substituted amines and amides, should we consider the "N" while deciding the order of substituents or simply place the substituents attached to nitogen in the beginning?
Ex- Should the compound be named
3-choloro-N-ethyl-4-methyl-N-propyl hexanamide
OR
N-choloro-N-propyl-3-choloro-4-methyl hexanamide. |
While naming substituted amines and amides, should we consider the "N" while deciding the order of substituents or simply place the substituents attached to nitogen in the beginning?
E.g. Should the compound be named:
- 3-chloro-N-ethyl-4-methyl-N-propylhexanamide
or
- N-chloro-N-propyl-3-choloro-4-met... |
While naming substituted amines and amides, should we consider the "N" while deciding the order of substituents or simply place the substituents attached to nitrogen in the beginning?
E.g. Should the compound be named:
- 3-chloro-N-ethyl-4-methyl-N-propylhexanamide
or
- N-chloro-N-propyl-3-chloro-4-met... |
The epoxide on the top of the picture, in aqueous acid hydrolyzes to the compound below. What is the mechanism of this reaction? Standard epoxide opening in acidic conditions would happen at the more substituted end, therefore the secondary -OH group would end up below the plane of the paper, and the tertiary center wo... |
I've recently read that trinitrophenol (picric acid - relative effectiveness factor $1.20$) is more explosive than trinitrotoluene (TNT - relative effectiveness factor $1.00$).
Personally, I think that the mesomeric effect of the oxygen's lone pairs in picric acid should keep the nitro groups 'happy', because of the... |
Why do we not need $\ce{H2SO4}$ as an acid catalyst for the di-nitration of [veratrole][1]?
![enter image description here][2]
Why does the 2nd nitro group go to positions 4 or 5, following the directing effects of the methoxy-group? Doesn't the first nitro group, that has been substituted onto the compound, have... |
*In CH4 1 s and 3 p orbitals are hybridised into 4 sp3 orbitals. But on homolytic bond cleavage an unpaired electron remains in unhybridised p orbital?
Similarly in heterolytic bond cleavage of CH4 methyl carbocation has an unhybridised empty p orbital? *
|
How does an hybridised orbital become unhybridised after bond cleavage? |
In $\ce{CH4}$, $1 s$ and $3 p$ orbitals are hybridised into $4 sp^3$ orbitals. But on homolytic bond cleavage an unpaired electron remains in unhybridised p orbital?
Similarly in heterolytic bond cleavage of $\ce{CH4}$ methyl carbocation has an unhybridised empty p orbital?
|
In $\ce{CH4}$, $1 s$ and $3 p$ orbitals are hybridised into four $sp^3$ orbitals. But on homolytic bond cleavage an unpaired electron remains in an unhybridised $p$ orbital?
Similarly in heterolytic bond cleavage of $\ce{CH4}$, the methyl carbocation has an unhybridised empty $p$ orbital?
|
Is $\ce{NaCl}$ in water aqueous? For a certain amount of $\ce{NaCl}$, it can dissolve in water but if you add more $\ce{NaCl}$ it can't dissolve any more.
So, if in a certain reaction $\ce{NaCl}$ is formed with water:
$$\ce{HCl(aq) + NaOH(aq) -> H2O(l) + NaCl(aq)}$$
My question is does $\ce{NaCl}$ in the previ... |
Is NaCl in water considered "solution" despite of NaCl's having some precipitation? |
> Standard epoxide opening in acidic conditions would happen at the more
> substituted end
This premise is false. Usually $\ce{S_{N}2}$ is faster than the cation-stabilized pathway (most textbooks don't even bother to explain the subtleties involved), yielding mainly the less substituted (less sterically hindered) ... |
Is the mechanism similar to the reaction of SOCl2 with alcohols?
If not, then how is it different?
We have been taught about the latter at school but my friend quizzed me about SO2Cl2. |
Does SO2Cl2 react with alcohols? |
Is the mechanism similar to the reaction of $\ce{SOCl2}$ with alcohols?
If not, then how is it different? We have been taught about the latter at school but my friend quizzed me about $\ce{SO2Cl2}$. |
Does SO2Cl2 react with alcohols, halides or any other func. group? |
Why is it important to mark solvent level on chromatography paper when you remove it from the petri dish? |
Building on my comment, marking the distance that the solvent traveled allows us to calculate the retention factor $R_f$ (or apparently [retardation factor](https://en.wikipedia.org/wiki/Retardation_factor), according to IUPAC meddlers who need to rename things with perfectly good names that everyone else uses). The re... |
I am trying to determine a method to dissolve a mineral salt with a lattice energy of ≈18000 kJ/mol. I know that lattice energy is the most significant factor affecting solubility of an ionic substance in highly polar solvents, and my general understanding is that more polar (or locally polar), the greater the abilit... |
What factors contribute most to solubility of ionic substances in highly polar solvents, esp. ionic liquids and DES? |
I have been working with octane and nonane. The neoprene seals in some of the apparatus are allegedly far more vulnerable to the deleterious effects of octane than nonane - why? [I assume it's a solvent thing] |
Octane, Nonane and Neoprene - why different reactions? |
I am trying to determine a method to dissolve a mineral salt with a lattice energy of ≈18000 kJ/mol. I know that lattice energy is the most significant factor affecting solubility of an ionic substance in highly polar solvents, and my general understanding is that the more polar (or locally polar), the greater the abil... |
How can hybrid orbitals be equivalent? Take, for example, $\mathrm{sp^3}$ hybridization. The wave functions of each hybrid orbitals are given by:
\begin{align}
\psi_1 &= \psi_s + \psi_{p_x} + \psi_{p_y} + \psi_{p_z}\\
\psi_2 &= \psi_s - \psi_{p_x} + \psi_{p_y} - \psi_{p_z}\\
\psi_3 &= \psi_s - \psi_{p_x} - \psi_{... |
How can hybrid orbitals be equivalent? |
On the physics site, I asked [the difference between real & complex orbital](http://physics.stackexchange.com/q/190726). Real orbitals are the superposition of complex orbitals having definite magnetic quantum number states.
\begin{align}
p_z &= p_0 \\
p_x &= \frac{1}{\sqrt{2}} \left(p_1 + p_{-1} \right) \\
p_y &... |
Why are real orbitals used to define the orbital of hydrogenic atoms instead of complex orbitals? |
Is it possible to calculate the energy of electron in any orbital and atom in the Schrödinger wave model theory? If so, how? E.g. energy of the $3s^2$ electron of the $\ce{Na-}$ ion. |
Is it possible to calculate energy of electron in any orbital and atom in Schrödinger wave model theory? |
While reading about nomenclature of branched alkyl groups, I read that certain common names are also approved by IUPAC. Among those names, only few prefixes are italicised (namely *sec* and *tert*) and others like iso and neo are printed normally. These names are documented in the [IUPAC blue book](http://www.acdlabs.c... |
Why Are 'sec' and 'tert' Prefixes Printed in Italics? |
While reading about nomenclature of branched alkyl groups, I read that certain common names are also approved by IUPAC. Among those names, only few prefixes are italicised (namely *sec-* and *tert-*) and others like iso- and neo- are printed normally. These names are documented in the [IUPAC blue book](http://www.acdla... |
Why Are 'sec-' and 'tert-' Prefixes Printed in Italics? |
While reading about nomenclature of branched alkyl groups, I read that certain common names are also approved by IUPAC. Among those names, only few prefixes are italicised (namely *sec-* and *tert-*) and others like iso and neo are printed normally. These names are documented in the [IUPAC blue book](http://www.acdlabs... |
What is the state of aggregation (gas, liquid) of oxygen in blood? |
The two commenters are collectively correct. But to clarify and augment their answers I would say that structure (d) cannot be correct because it is missing 2 carbon atoms relative to (c), and if you tried to cyclize (c) by forming esters, the result would be highly strained. Try making a molecular model of it and see ... |
![enter image description here][1]
The question was to rationalize it the ring cleavage happens concerted or non-concerted.
The papers *"The Mechanism of the Thermal Decomposition of
1-Pyrazolines and Its Relationship to
Cyclopropane Isomerizations"* (Crawford 1965/1966) have shown the loss of $\ce{N_2}$ is... |
Why does hyperconjugation help for ring cleavage? |
Why is has the Ziegler-Natta polymerization the regioselectivity shown in the image? Internal (coordinated to the metal) nucleophiles should attack the alkene on the less substituted end like in the Heck reaction. Why is the regioselectivity different here? External nucleophile should attack the more substituted end (l... |
I've noticed there are a lot of different grouping in the periodic tables I can find online.
I'm referring to the
- alkali metals
- alkaline earth metals
- transition metals
- lanthanides
- etc.
For example, these tables have different groups, although quite similar.
- http://i.telegraph.co.uk/multimedi... |
Periodic table groups - which one is "right"? |
Why are 'sec-' and 'tert-' prefixes printed in iItalics? |
Periodically in our lab, we have a reproducibility test for the various samples that we analyze. One such sample is boiler water. Two of the parameters that we test are phosphate in boiler water and iron in boiler water. Random error aside (shaking of sample, measurement bias, etc.), why are my iron results usually low... |
Why are 'sec-' and 'tert-' prefixes printed in italics? |
I've noticed there are a lot of different grouping in the periodic tables I can find online.
I'm referring to the
- alkali metals
- alkaline earth metals
- transition metals
- lanthanides
- etc.
For example, these tables have different groups, although quite similar. For example, mercury is sometimes in th... |
I've noticed there are a lot of different grouping in the periodic tables I can find online.
I'm referring to the
- alkali metals
- alkaline earth metals
- transition metals
- lanthanides
- etc.
For example, these tables have different groups, although quite similar. For example, mercury is sometimes in th... |
I've noticed there are a lot of different grouping in the periodic tables I can find online.
Take Mercury in the two linked tables, for example.
On the first table, it's explicitly outside of the transition metals. On the second table, it's in the "transition metals" group.
- http://i.telegraph.co.uk/multimedia/... |
Periodic table groups - which grouping is "right"? |
Why is it important to mark solvent level on chromatography paper when you remove it from the chamber? |
Why note the solvent level on chromatography paper when it is removed from the chamber? |
In searching online, I've noticed there are a lot of different ways to group the elements of the periodic table.
Take mercury in the two tables linked below, for example:
- http://i.telegraph.co.uk/multimedia/archive/02101/periodic_2101916b.jpg
- http://www.sciencegeek.net/tables/PToE_basic.pdf
On the first t... |
I’m trying to do some quantum chemical calculations for the linear molecule $\ce{FeP2}$ in the gas phase as well as its crystal ([orthorhombic symmetry like here][1]). I am lead to believe that in both cases iron has an oxidation state of +6, and phosphorous has an oxidation state of −3. My questions are:
* Are such... |
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