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What does it mean that "When vapor pressure of solid is greater than liquid, there is a net conversion from solid to liquid".
What exactly occurs in the process of solidification of liquids? |
How does solidification occur? |
Last week there was a huge fire in french chemical factory Lubrizol, we now know the main products that burnt, to simplify the discussion I extracted a few compounds:
- [isobutyl and isobutene polysulfide](https://patents.google.com/patent/US4839069) 500 tons,
- [dithiophosphoric acid and corresponding zinc sal... |
**Lassaigne's method:**
The organic compound is fused with dry $Na$ in a fusion tube. The fused mass after extraction with water is boiled and filtered. This filtrate is called sodium extract (S.E.), which is used to detect elements other than $\ce{C}$ and $\ce{H}$ in organic compound.
If the organic compound con... |
When will the Lassaigne's method for detection of nitrogen and Kjeldahl's method for quantitative estimation of nitrogen fail? |
First things first: [the bonding orbitals of $\ce{I3-}$ do not contain any significant d-orbital contributions][1]. In fact, [the $\ce{I-I}$ bond lengths are significantly longer than in $\ce{I2}$, suggesting a lower bond order][2].
In fact, the triiodide anion should rather be imagined as a 4-electron-3-centre bond... |
I have almost the whole night trying to identify this structure with no avail as there is always one part that does not fit. The determined formula for this structure was **C13H17BrO** from the m/z=268 (M-100%), m/z=269 (M+1-14.7%), and m/z=270 (M+2-98.6%).
The 1 H-NMR data is as follows with integration in parenthe... |
I have almost the whole night trying to identify this structure with no avail as there is always one part that does not fit. The determined formula for this structure was **C13H17BrO** from the m/z=268 (M-100%), m/z=269 (M+1-14.7%), and m/z=270 (M+2-98.6%).
The 1 H-NMR data is as follows with integration in parenthe... |
I have recently purchased a cleaning solution for precision optics which has the following ingredients (amounts were not specified):
- Ethyl Alcohol
- Methylethylketon
- Aqua
- Diethyl Ether
- Isopropyl
Typically reagent grade isopropyl alcohol alone is used for cleaning optical elements. So, does the mi... |
Is it possible to make graphite oxidize in the presence of oxygen?
I know it's possible to make other forms of carbon oxidize and even burn with the production of residual heat in the presence of oxygen.
As far as I know graphite is very resistant to heat, and it isn't possible to make it burn even at high tempe... |
Molybdenum(VI) fluoride can be used as a fluorinating agent though not as popular as the selective DAST and Deoxyfluor as @Waylander noted. Molybdenum(VI) fluoride fall under the category of electrophilic fluorinating agent where it acts as a Lewis acid. The reaction is run in an inert solvent like $\ce{CH2Cl2}$ and a ... |
You are right about the limitations of century old Lassaigne's method. Why are they still teaching it? Modern day CHNSO elemental analysis is done with gas chromatograpy systems. If you are quoting from a book, provide a reference.
This is an excerpt from a 1953 work *Sulfur in Organic Compounds, by a Modified. Lass... |
**In physics the dipole moment** is said to go **from the negative to the positive pole**, check for instance https://en.wikipedia.org/wiki/Electric_dipole_moment (Elementary definition).
This makes sense to me since in an electric field (which is directed from positive to negative) the dipole moment aligns with th... |
Why does the dipole moment of molecules go from positive to negative? |
You have assessed the problem correctly. Physicists and chemists use just the opposite directions. Keep in mind that both are arbitrary choices, however the physicist's convention is consistent with electrostatics. All you have to do is to be aware of this direction in the chemistry literature. I have rarely seen any s... |
Recently, looking into structures of buckminsterfullerenes, I have found several articles claiming that attaching 12, or “several” nitrous oxide molecules to the buckminsterfullerene will cause it to degrade exothermically, heating the surroundings to several thousand degrees in “picoseconds”. The degradation would pro... |
Recently, looking into structures of buckminsterfullerenes, I have found several articles claiming that attaching 12, or “several” nitrous oxide molecules to the buckminsterfullerene will cause it to degrade exothermically, heating the surroundings to several thousand degrees in “picoseconds”. The degradation would pro... |
> This doesn't make any sense to me, is there any good reason for this discrepancy?
Provided you remember the convention you are using it shouldn't matter. You could argue that either way "makes sense". If you draw it the way that you suggest is logical, then you are right, the low energy configuration will point th... |
> This doesn't make any sense to me, is there any good reason for this discrepancy?
Provided you remember the convention you are using it shouldn't matter. You could argue that either way "makes sense". If you draw it the way that you suggest is logical, then you are right, the low energy configuration will point th... |
> This doesn't make any sense to me, is there any good reason for this discrepancy?
Provided you remember the convention you are using it shouldn't matter. You could argue that either way "makes sense". If you draw it the way that you suggest is logical, then you are right, the low energy configuration will point th... |
Not glass *per se*, but silica is often produced chemically by [silicon alkoxide gelation][1] to create aerogels.
The problem with creating glass by some cold process would be that the reaction side-products, such as water, would have to be removed, leaving holes in a froth of glass. This is fine for creating an aer... |
What is the mechanism of halogenation of carbonyl compounds using molybdenum hexafluoride? How does it work?
Here's a reaction I came across:
[![halogenation of carbonyl compounds using molybdenum hexafluoride][1]][1]
Can we use it for all carbonyl compounds? Are there any limitations to the method?
[... |
In Thompson's [_Illustrated Guide to Home Chemistry Experiments_](http://shop.oreilly.com/product/9780596514921.do) the chemical formula for Schweizer's reagent is represented as $\ce{[Cu(NH3)4](OH)2}$ (although [Wikipedia](https://en.wikipedia.org/wiki/Schweizer%27s_reagent) represents it as $\ce{[Cu(NH3)4(H2O)2](OH)2... |
Balanced equation for Schweizer's reagent production? |
I have almost the whole night trying to identify this structure with no avail as there is always one part that does not fit. The determined formula for this structure was $\ce{C13H17BrO}$ from the $m/z=268$ (M-100%), $m/z=269$ (M+1-14.7%), and $m/z=270$ (M+2-98.6%).
The $\ce{^1H}$-NMR data is as follows with integra... |
I saw that $\ce{NO2}$ is oxidized really fast, but if I put $\ce{SO2}$ in a jar with air at STP, will it take hours, days or years to react into $\ce{SO3}?$ |
How much time does sulfur dioxide take to oxidize to trioxide in air? |
Expanding on Jan's reference to three-center four-electron bonding:
When the three iodine atoms all come together in a line the overlap among all three atoms gives the combination of $p$ orbitals rendered thusly ([source](https://en.m.wikipedia.org/wiki/Three-center_four-electron_bond)):
![enter image description... |
I was just introduced to the concept of orbital hybridization. I believe I understand the idea behind it, but there is some accompanying terminology that prevents me from achieving a greater understanding.
In the following image:
[![enter image description here][1]][1]
I see that one of the electrons in the $... |
The dipole moment of quinol is not zero because it can exist in two different energetically favourable conformations. The weighted average is calculated to arrive a dipole moment of 1.6 D.
According to wikipedia, the dipole moment of terephthalic acid is zero <https://en.wikipedia.org/wiki/Terephthalic_acid>.
But f... |
What can we say about the dipole moment of terephthalic acid? |
When I was an undergrad, roughly around 2005, I took a grad level class that covered various topics in advanced organic synthesis. I don't remember much clearly from the class, but one thing that I can't forget was this one reaction where a single chain compound was, in one step, cyclized to a multi-ring system (maybe ... |
What is the largest one step radical cyclization ever achieved? |
In my quest for a non-electrochemical glyoxylic acid synthesis, I've found a few that seem simple and pretty OTC. The first is the reduction of oxalic acid with magnesium metal, which if I'm not mistaken forms a magnesium salt which is unwanted. The second is a mixture of nitric acid and ethyl alcohol, which I couldn't... |
The dipole moment of quinol is not zero because it can exist in two different energetically favourable conformations. The weighted average is calculated to arrive a dipole moment of 1.6 D.
According to [Wikipedia](https://en.wikipedia.org/wiki/Terephthalic_acid), the dipole moment of terephthalic acid is zero.
But ... |
On another thread on this website it mentioned how it was possible to melt diamonds, but what would be the micro-level occur for that to happen. This question applies to Silicon Oxide aswell. They both have infinite structures. Which bonds would break or even weaken for them to transition states? For example, when a re... |
How is it possible to melt diamonds? |
In the 3rd step of cryogenic air separation, filtered air is purified to remove water, CO2, and hydrocarbons from the N2-O2-Ar stream. Im interested in knowing what happens with that CO2 and water. Can both resources be recovered in a useful form? Can the CO2 be purified/ are Praxair or others currently doing this?
... |
Do companies recover CO2 and water from the purification step of cryogenic air separation, and how? |
This is typically with reference the mass balance problems in Iron Making.Whenever we are asked to mole balance $SiO_2$ it is treated this way $W_{SiO_2}$from iron ore+$W_{SiO_2}$ from coke=**$W_{SiO_2}$ in the form of $W_{Si}$** in hot metal+$W_{SiO_2}$ in slag.Please explain the meaning of the highlighted part.What i... |
What does it mean to calculate "weight of $SiO_2$ in the form of Si"? |
In the 3rd step of cryogenic air separation, filtered air is purified to remove water, $\ce{CO2},$ and hydrocarbons from the $\ce{N2}$-$\ce{O2}$-$\ce{Ar}$ stream. Im interested in knowing what happens with that $\ce{CO2}$ and water. Can both resources be recovered in a useful form? Can the $\ce{CO2}$ be purified? Are P... |
Do companies recover carbon dioxide and water from the purification step of cryogenic air separation, and how? |
> This doesn't make any sense to me, is there any good reason for this discrepancy?
Provided you remember the convention you are using it shouldn't matter. You could argue that either way "makes sense". If you draw it the way that you suggest is logical, then you are right, the low energy configuration will see the ... |
This is with reference to the typical mass balance problems in iron making. Whenever we are asked to mole balance $\ce{SiO_2}$ it is treated this way:
$W_{\ce{SiO_2}}$from iron ore+$W_{\ce{SiO_2}}$ from coke=**$W_{\ce{SiO_2}}$ in the form of $W_{\ce{Si}}$** in hot metal+$W_{\ce{SiO_2}}$ in slag.
Please explain th... |
I learnt that litmus paper can be bleached by chlorine to turn colorless. I’m wondering if there are any chemical substances that can react with all the components of universal indicator such that it turns colorless, or stops being a pH indicator? |
Can universal indicator turn colourless? |
> This doesn't make any sense to me, is there any good reason for this discrepancy?
Provided you remember the convention you are using it shouldn't matter. You could argue that either way "makes sense". If you draw it the way that you suggest is logical, then you are right, the low energy configuration will see the ... |
Expanding on Jan's reference to three-center four-electron bonding:
When the three iodine atoms all come together in a line the overlap among all three atoms gives the combination of $p$ orbitals rendered thusly ([source](https://en.m.wikipedia.org/wiki/Three-center_four-electron_bond)):
):
, the dipole moment of terephthalic acid is zero.
But ... |
Expanding on Jan's reference to three-center four-electron bonding:
When the three iodine atoms all come together in a line the overlap among all three atoms gives the combination of $p$ orbitals rendered thusly ([source](https://en.m.wikipedia.org/wiki/File:Triiodide_molecular_orbitals.png)):
![enter image descr... |
Expanding on Jan's reference to three-center four-electron bonding:
When the three iodine atoms all come together in a line the overlap among all three atoms gives the combination of $p$ orbitals rendered thusly (source: [Wikipedia by Arun Sridharan](https://en.m.wikipedia.org/wiki/File:Triiodide_molecular_orbitals.... |
In the 3rd step of cryogenic air separation, filtered air is purified to remove water, $\ce{CO2},$ and hydrocarbons from the $\ce{N2}$-$\ce{O2}$-$\ce{Ar}$ stream. Im interested in knowing what happens with that $\ce{CO2}$ and water. Can both resources be recovered in a useful form? Can the $\ce{CO2}$ be purified? Are P... |
This is with reference to the typical mass balance problems in iron making. Whenever we are asked to mole balance $\ce{SiO_2}$ it is treated this way:
$W_{\ce{SiO_2}}$ from iron ore + $W_{\ce{SiO_2}}$ from coke = **$W_{\ce{SiO_2}}$ in the form of $W_{\ce{Si}}$** in hot metal+$W_{\ce{SiO_2}}$ in slag.
Please expla... |
What does it mean to calculate "weight of SiO2 in the form of Si"? |
#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... |
As stated I am not a chemist, but I need help on a question I have.
Assume I have a Formic acid 75% and I add between 5-10 kg to 1.000 liter of water. If I wanted to add sodium formate and HCl 37% to water and achieve a similar result with regards to pH and "pure" undissociated formic acid how much of each product ... |
My professor said that in order to have PI, both + and - charge have to exist, and therefore phosphoric acid cannot have a Pi. I am confused because I can't find any definition that states both + and - charge need to exist on text or online. Online, the definitions of PI indicates something similar to "at which the mol... |
I would like to know if there is a proper way to get the 3D information from the [SMILES][1] string of a molecule.
1. Is there a standard way to embed a SMILES string in 3D space?
2. Are there other representations of compounds which include their spatial information too?
[1]: https://en.wikipedia.org... |
The solubility of sodium acetate is interesting (that means confusing!). Sodium acetate exists in two forms: anhydrous and trihydrate. When compounds exist in two forms like this, the solubilities, given in grams per 100 mL H20, are predictable: the hydrated form is much more soluble, because it is only partially the c... |
I've been referring the book: Chemical Process Principles: Part-II Thermodynamics. I found a table that gives me fugacity coefficients in a tabular form corresponding to various reduced pressures and reduced temperatures. This is it:
I dont know... |
What are D_b and D_a in the Generalized Fugacity Coefficients table? |
I am checking out [Wikipedia][1] and it shows a different melting point for l-menthol (42 to 45 C) vs dl-menthol (36 to 38 C).
How is this possible? d-menthol and l-menthol being [enantiomers][2], shouldn't they have identical physical properties including the MP?
> The two enantiomers of a molecule possess the... |
d menthol vs dl menthol; Enantiomers have different melting points? |
I have browsed internet to understand the concept of vapour pressure but something isn't linking for me. How do we relate vapour pressure to temperature for liquid only and any simplified definition of vapour pressure would be more than welcome! Can we relate vapour pressure to critical temperature in any way? Thanks i... |
>Ammonium carbamate dissociates as follows:
>$\ce{NH2COONH4(s)<=> 2NH3(g) + CO2(g)}$
>The value of $K_p$ for this reaction is found to be equal to
$\pu{2.92 * 10^-5 atm^3}$. If one mole of ammonium carbamate is heated in a sealed container, the total pressure develped in the container is
(A) 0.0194 atm
(B) 0.0... |
I am checking out [Wikipedia][1] and it shows a different melting point (m.p.) for *l*-menthol ($42$ to $\pu{45 ^\circ C}$) vs *dl*-menthol ($36$ to $\pu{38 ^\circ C}$).
How is this possible? *d*-menthol and *l*-menthol being [enantiomers][2], shouldn't they have identical physical properties including the m.p.?
... |
d-Menthol vs dl-menthol: Does an enantiomer and its racemic mixture have different melting points? |
When visiting a botanical garden in Stockholm I have stumbled across the following mosaic tile:
[![Chemical formula][1]][1]
I have tried to identity it using [MolView][2], but it does not seem to identify it. Also, I have tried their advanced search (similarity), but that provided no results.
I have also trie... |
How can I find out a substance name based on its structural formula? |
During lecture, we were learning how to draw the MO diagram for BF3.
I understand that only orbitals with the same symmetry labels can interact and form molecular orbitals. My professor always elaborate a lot on "phase matching" and he would draw the orbitals out.
However, I don't understand how the diagrams are s... |
What is the purpose of phase matching when drawing a MO diagram? |
During lecture, we were learning how to draw the MO diagram for BF3.
I understand that only orbitals with the same symmetry labels can interact and form molecular orbitals. My professor always elaborate a lot on "phase matching" and he would draw the orbitals out.
However, I don't understand how these orbital draw... |
I am checking out [Wikipedia][1] and it shows a different melting point (m.p.) for *l*-menthol $(\pu{42 ^\circ C}$ to $\pu{45 ^\circ C})$ vs *dl*-menthol $(\pu{36 ^\circ C}$ to $\pu{38 ^\circ C}).$
How is this possible? *d*-menthol and *l*-menthol being [enantiomers][2], shouldn't they have identical physical prope... |
During the lecture, we were learning how to draw the MO diagram for $\mathrm{BF_3}$.
I understand that only orbitals with the same symmetry labels can interact and form molecular orbitals. My professor always elaborates a lot on "phase matching," and he would draw the orbitals out.
However, I do not understand how... |
If a relatively unventilated area, like a basement, were to be exposed to radon gas (Rn-222), would the dust in the area possess a detectable amount of lead? Considering lead 214 is a decay product of radon 222, will a room exposed to radon gas possess dust with a detectable and differentiable amount of lead relative t... |
Can the presence of radon (Rn-222) be determined by testing dust? |
I learned that litmus paper could be bleached by chlorine to turn colorless. I’m wondering if any chemical substances can react with all the components of a universal indicator such that it turns colorless, or stops being a pH indicator? |
Can a universal indicator turn colorless? |
### Question
> We have the following chemical reactions:
> $$
\begin{align}
\ce{A + B^* &-> C + D^*}\tag{1}\\
\ce{D^* &-> B^* + B^*}\tag{2}\\
\ce{B^* &-> B}\tag{3}
\end{align}
$$
> If the initial concentrations are $[\ce{A}] = \pu{100e-6 mol cm-3}$ and $[\ce{B}] = \pu{1e-6 mol cm-3}$, is the system explo... |
### Question
> We have the following chemical reactions:
> $$
\begin{align}
\ce{A + B^* &-> C + D^*}\tag{1}\\
\ce{D^* &-> B^* + B^*}\tag{2}\\
\ce{B^* &-> B}\tag{3}
\end{align}
$$
> If the initial concentrations are $[\ce{A}] = \pu{100e-6 mol cm-3}$ and $[\ce{B}] = \pu{1e-6 mol cm-3}$, is the system explo... |
When visiting a botanical garden in Stockholm, I stumbled across the following mosaic tile:
[![Chemical formula][1]][1]
I have tried to identify it using [MolView][2], but it does not seem to identify it. Also, I have tried their advanced search (similarity), but that provided no results.
I have also tried se... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow. To my mind, this also disconnects them from their typical usage.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: ... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: A reaction for which the overall standard enthalpy change ΔH⚬ is n... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: A reaction for which the overall standard enthalpy change ΔH⚬ is n... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: A reaction for which the overall standard enthalpy change ΔH⚬ is n... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: A reaction for which the overall standard enthalpy change ΔH⚬ is n... |
In stereochemical vocabulary, a racemic mixture (racemate) is one that has equal amounts (50:50) of left- and right-handed ($d$- and $l$-) enantiomers of a chiral molecule. According to [Wikipedia: Racemic Mixture](https://en.wikipedia.org/wiki/Racemic_mixture#cite_note-4), a racemic mixture can be crystallized in four... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: A reaction for which the overall standard enthalpy change $ΔH^⚬$ i... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: A reaction for which the overall standard enthalpy change $ΔH^⚬$ i... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
exothermic reaction: A reaction for which the overall standard enthalpy change $ΔH^⚬$ i... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
> exothermic reaction: "A reaction for which the overall standard
> enthalpy change $Δ... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
> exothermic reaction: "A reaction for which the overall standard
> enthalpy change $Δ... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
> exothermic reaction: "A reaction for which the overall standard
> enthalpy change $Δ... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
> exothermic reaction: "A reaction for which the overall standard
> enthalpy change $Δ... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
> exothermic reaction: "A reaction for which the overall standard
> enthalpy change $Δ... |
I'm wondering if anyone can provide a rationale for IUPAC's definitions of exothermic and endothermic, since they disconnect these terms from the direction of heat flow.
Specifically, here are IUPAC's *Gold Book* definitions:
> exothermic reaction: "A reaction for which the overall standard
> enthalpy change $Δ... |
Suppose you had a single sheet of graphite the size of an A4 page. What would it feel like to handle it?
Would your fingers instantly tear through it as you tried to grasp it?
Could you punch your finger through on purpose?
Could you tear it like a sheet of paper?
Could you fold it into a paper aeroplane wi... |
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