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I have science-fiction related reasons for being very interested in liquid carbon (tidally heated carbon-rich planemo), so I've looked into it a bit. Liquid carbon exists at high pressures and very high temperatures. I think the main problem is the temperatures, since barely anything is solid under conditions where car... |
>Why is the molozonide adduct thermally unstable?
The molozonide adduct (1,2,3-trioxalane; the initial adduct by 1,3-dipolar cycloaddition of alkene and ozone) is thermally unstable because it contains two weak $\ce{O-O}$ bonds (Ref.1). Mechanistic studies reveal that the ozonide (1,2,4-trioxalane) is formed by a se... |
While going through my book, I came across this question and got really confused. Here's what the problem was:
> In a pair of diastereomers,
>1. Both can be laevo-rotatory or both can be dextro-rotatory
>2. Both can be optically inactive
>3. One can be optically active other can be optically inactive
>4... |
In a pair of diastereomers, which of the following is true? |
Can anyone explain me that how the coordination number of corner sphere of this 3-D packing is 6 ? it should be 3
[![3D close packing from 2-D square close packed layers][1]][1]
[1]: https://i.stack.imgur.com/4pqQa.jpg |
In organic chemistry, both the D, L system and the (+), (-) system are widely used, in conjunction with the modern (R, S) system.
The D, L system names an organic molecule based on the direction that its bottom -OH group points at, when the molecule is drawn with the most oxidized carbon on top in the Fischer proje... |
I am still very confused with the bromination of alkenes. Can I ask help in finding the structure of the main product when each of these 3 are subjected to photochemical bromination? I know for a fact that the Br will replace an H atom, but I don't know what to do anymore if there's another functional group present at ... |
The following compound undergoes ring expansion and contraction simultaneously.
<br>I am not able to figure out a clear mechanism for the same, and stuck for a lot of time to get this clear. <br>Kindly help me out with the same by using appropriate mechanism or models.
[![enter image description here][1]][1]
<b... |
Given Fischer's projections of a few stereoisomers of some compound, how can we find out if they are enantiomers, diastereomers, etc.? From what I understand, we can rotate the projections to have the same groups on the top and bottom and then compare (non-superimposable mirror images --> enantiomers, non-mirror image ... |
This is the exact question I faced on an exam.
Calculate the pH of $\pu{0.05 M}\ \ce{Na2CO3}\ (\ce{H2CO3}: K_\mathrm{a,1}= 4\times 10^{-7},\ K_\mathrm{a,2}= 4.7\times 10^{-11})$
### Solution ###
$$\ce{Na2CO3 ->2Na+ + CO3^2-}$$
I suppose nothing that can contribute to the pH of a solution happens to $\ce{Na+}$... |
I have encountered this reaction when I am learning entropy:
[![][1]][1]
I don't understand why there is an increase in entropy.
What I am thinking is:
1. both reactants and products are in the same states, so there isn't any change in entropy in terms of states.
2. both the reactant and products have the ... |
I'm just now learning about the Fourier transform, which seems like a pretty useful tool, and I know it has uses in spectroscopy (e.g. FTIR) since that is what Google shows when searching for applications of the Fourier transform in chemistry. Interestingly, I found out that the Laplace transform can be used in
[chem... |
I have encountered this reaction when I am learning entropy:
[![][1]][1]
I don't understand why there is an increase in entropy (said to be slightly larger than 0).
What I am thinking is:
1. both reactants and products are in the same states, so there isn't any change in entropy in terms of states.
2. both... |
This is a fun one, and a common question in this course. First, as you say, H and Br are lost by anti elimination, since they helpfully tell you base and E2 are involved. That means the H and Br are lost from opposite faces of the future double bond, leaving us with a trans intermediate that has a mirror plane (the p... |
Lithium is known to have the highest ionization energy among Group 1 elements. Also, characteristic colours in the flame test arise due to the excitation and de-excitation of electrons. Then why Lithium gives Crimson Red colour in the Flame test, why not a colour corresponding to a higher frequency like Purple or Blue ... |
I have a Physics question for which I could not find the answer on the Internet, so I would like to see if y'all know the answer to it.
I have found that heavy water will have a different boiling point compared to light water, and this trend is present between various isotopes of an element. Based on this research, ... |
Can the enrichment of Uranium be done via manipulating the boiling/melting point difference between differing isotopes of the same element? |
I've been told by my teacher that Corey-House synthesis cannot proceed with 2° alkyl halides; they will prefer to undergo Elimination over SN2 substitution. [used as the pseudo halide, not the diorganyl cuprate.]. My book, however says that 2° alkyl halides do undergo the reaction. A quick google search on Wikipedia sa... |
Corey-House synthesis: Are 2° Alkyl Halides usable? |
As far as I know, to non-polar molecules like CF<sub>4</sub> and C<sub>2</sub>H<sub>6</sub>,
boiling point is mainly affected by the London dispersion force.
<p>As a result, molecules with more protons and electrons normally have higher boiling points.
<p>However, CF<sub>4</sub> (34 electrons) has a boilng point of... |
Why does CF4 have a lower boiling point than C2H6, despite having more electrons? |
As far as I know, to non-polar molecules like CF<sub>4</sub> and C<sub>2</sub>H<sub>6</sub>,
boiling point is mainly affected by the London dispersion force.
<p>As a result, molecules with more protons and electrons normally have higher boiling points.
<p>However, CF<sub>4</sub> (34 electrons) has a boilng point of... |
Why do fluoride moleculeds seem to have abnormally low boiling points? |
In the section Brønsted-Lowry acid and base theory from Khan Academy:
> In the reaction $\ce{LiOH(aq) + HBr(aq) -> H2O(l) + LiBr(aq)}$, $\ce{HBr}$ is donating a proton to $\ce{LiOH}$, thus acting as a Brønsted-Lowry acid. Since $\ce{LiOH}$ accepts the proton, it is acting as a Brønsted-Lowry base.
>
> Image sourc... |
"HBr is donating a proton to LiOH": Why doesn't it produce LiOH2? |
Why do fluoride molecules seem to have abnormally low boiling points? |
I know a value of h^2 + k^2 + l^2 = 7 is not allowed but I cannot understand where I am going wrong with the indexing here. Any insight would be greatly appreciated as I am wondering if this is made up data that has a typo? I calculated d using d= wavelength/(2sin(theta)) where theta is half the value of 2theta (obviou... |
I thought it is just me, but when I [searched it on Google][1], it revealed that there are many people who experience this:
Why is it that whenever I taste my own blood, I always think it tastes like rust? I have never eaten or tasted rust, so how can I relate something to it?
[1]: https://www.google.com.ph/se... |
I've been told by my teacher that the Corey–House synthesis cannot proceed with secondary alkyl halides; they will prefer to undergo elimination over $\mathrm{S_N2}$ substitution. [used as the pseudo halide, not the diorganyl cuprate.]. My book, however says that secondary alkyl halides do undergo the reaction. A quick... |
Can secondary alkyl halides be used in the Corey–House synthesis? |
I know a value of $h^2 + k^2 + \ell^2 = 7$ is not allowed but I cannot understand where I am going wrong with the indexing here. Any insight would be greatly appreciated as I am wondering if this is made up data that has a typo? I calculated d using $d= \lambda{} /(2\sin{\theta{}})$ where $\theta$ (theta) is half the v... |
I'm trying to construct an MO diagram for cisplatin, which has C2v symmetry. However, there is no Mulliken label for the d(x^2-y^2) orbital in the character table. Does this orbital not form molecular orbitals in C2v symmetry? |
I have some Canadian and British bank notes. The first issue is that I don't know if they're paper or plastic.
Second, I don't understand [this answer](https://lifehacks.stackexchange.com/questions/19672/how-can-i-sanitize-paper-money). Why's it safe to iron paper bills? Won't the heat or pressure ruin the paper bi... |
Why can you sanitize paper money notes with a Clothes Iron? |
I'm trying to calculate the pH of a 0.10 M solution of ammonium acetate, and I am struggling to find what mistake I am making within the following calculations:
We know that $\dfrac{[\ce{NH3}][\ce{H^{+}}]}{[\ce{NH4^{+}}]} = K_a = 5.6 \times10^{-10}$, and that $\dfrac{[\ce{CH_3COOH}]}{[\ce{CH3COO^{-}}][\ce{H+}]} = K... |
All of the (believable) sources at [PubChem][1] and most of the sources at [NIST][2] give 181 K for the melting point.
The one source I can find for the triple point is NIST, which gives 155 K.
There are two possibilities I can think of, but I can't confirm or deny either:
1. The triple point value is wrong.
... |
Why is the reported melting point of formaldehyde so different from the triple point? |
How does the relationship between carbonate, ph, and disolved CO$_2$ work in water? |
How does the relationship between carbonate, pH, and dissolved carbon dioxide work in water? |
Perhaps I’m still having issues with significant figures, but I am getting the wrong answer for the following:
A sample of uranium fluoride is found to effuses at the rate of 17.7 mg/hr. Under comparable conditions, gaseous iodine effuses at the rate of 15.0 mg/hr. What is the molar of the uranium fluoride?
So I know... |
In lecture I was taught that, in a galvanic cell at standard conditions, platinum is often used as an inert electrode when the species being oxidized or reduced exists only in solution, because platinum is "inert," which means it is very stable at and resists reduction or oxidation. This concept confuses me for two rea... |
All of the (believable) sources at [PubChem][1] and most of the sources at [NIST][2] give 181 K for the melting point.
The one source I can find for the triple point is NIST, which gives 155 K.
There are two possibilities I can think of, but I can't confirm or deny either:
1. The triple point value is wrong.
... |
All of the (believable) sources at [PubChem][1] and most of the sources at [NIST][2] give 181 K for the melting point.
The one source I can find for the triple point is NIST, which gives 155 K.
There are two possibilities I can think of, but I can't confirm or deny either:
1. The triple point value is wrong.
... |
All of the (believable) sources at [PubChem][1] and most of the sources at [NIST][2] give 181 K for the melting point.
The one source I can find for the triple point is NIST, which gives 155 K.
There are two possibilities I can think of, but I can't confirm or deny either:
1. The triple point value is wrong.
... |
Perhaps I’m still having issues with significant figures, but I am getting the wrong answer for the following:
A sample of uranium fluoride is found to effuses at the rate of 17.7 mg/hr. Under comparable conditions, gaseous iodine effuses at the rate of 15.0 mg/hr. What is the molar of the uranium fluoride?
So I know... |
I've done this experiment myself and seen it front of my eyes. Set up a basic circuit with a battery, an LED, and connect the circuit with a salt-water solution and copper wire. The LED lights up.
If a potential difference is applied across two ends of the wire with the battery, positive charges move towards the end... |
Would ionic conduction be halted by shielding at the electrodes? |
I'm trying to calculate the $\mathrm{pH}$ of a $\pu{0.10 M}$ solution of ammonium acetate, and I am struggling to find what mistake I am making within the following calculations:
We know that $\dfrac{[\ce{NH3}][\ce{H^{+}}]}{[\ce{NH4^{+}}]} = K_\mathrm{a} = 5.6 \times10^{-10}$, and that $\dfrac{[\ce{CH_3COOH}]}{[\ce... |
Almost all Alkali metals and Alkaline Earth metals react with air to form respective oxides,but why does only Magnesium forms a protective oxide layer. What properties of magnesium oxide allow it to form a layer? I tried to search this but couldn't find any explanation. |
You are completely right that ions migrate at different rates, and the relative rates can be quantified by a property of the electrolyte called the transport number, which is the fraction of the current that can be accounted by one of the ions:
$$t_\circ^+ = \frac{\Lambda_\mathrm{m}^\circ(\ce{A+})}{\Lambda_\mathrm{m... |
You are completely right that ions migrate at different rates, and the relative rates can be quantified by a property of the electrolyte called the transport number, which is the fraction of the current that can be accounted by one of the ions:
$$t_\circ^+ = \frac{\Lambda_\mathrm{m}^\circ(\ce{A+})}{\Lambda_\mathrm{m... |
[![enter image description here][1]][1]
**The given solution:**
**[![strong text][2]][2]**
Now, here is why I am confused: this calculation is for a buffer solution, where HA and A- are a conjugate acid/base pair. however, chloroethanoic acid and sodium hydroxide are not conjugate acid/base (are they?) - so w... |
Calculating the pH of a 'buffer' solution? |
Question: **Determine the pH of the solution resulting when 100cm^3 of 0.50 mol dm^-3 CH2ClCOOH is mixed with 200cm^3 of 0.10dm^-3 NaOH.**
**The given solution:**
**[![strong text][2]][2]**
Now, here is why I am confused: this calculation is for a buffer solution, where HA and A- are a conjugate acid/ba... |
> **Question:** Determine the pH of the solution resulting when $100cm^3 \text{ of } 0.50 mol\cdot {dm}^{-3}$ $ \ce{CH2ClCOOH} \text{ is mixed with } 200cm^3 \text{ of } 0.10$ $ {dm}^{-3}\text{ } \ce{NaOH}.$
**The given solution:**
**[![strong text][2]][2]**
Now, here is why I am confused: this ... |
$\ce{CH2ClCOOH}$ is a weak acid; $\ce{NaOH}$ is a strong base. Now, tell me, what do you think happens when you mix a strong base with a weak acid?
## They react.
$$\ce{CH2ClCOOH + NaOH -> CH2ClCOONa + H2O} $$A neutralisation reaction in aqueous medium depends upon the number of equivalents of acid and base.
$$N_... |
How can platinum function as an "inert electrode" while having a standard reduction potential of 1.2 from its 2+ oxidation state? |
Here is where I'm at so far with trying to answer this question:
Is the particle in a box concept analogous to an electron in an orbital? If so, can we apply the equation for the allowed energies of a particle in a box (E = (hn^2)/(8mL^2)), to the allowed energies of electrons in orbitals. If so, are the orbitals de... |
How does the application of Schrodinger's equation to model a particle in a box explain the degeneracy of atomic orbitals? |
$\ce{CH2ClCOOH}$ is a weak acid; $\ce{NaOH}$ is a strong base. Now, tell me, what do you think happens when you mix a strong base with a weak acid?
## They react.
$$\ce{CH2ClCOOH + NaOH -> CH2ClCOONa + H2O} $$
A neutralisation reaction in aqueous medium depends upon the number of equivalents of acid and base.
... |
I've done this experiment myself and seen it front of my eyes. Set up a basic circuit with a battery, an LED, and connect the circuit with a salt-water solution and copper wire. The LED lights up.
If a potential difference is applied across two ends of the wire with the battery, positive charges move towards the end... |
> **Question:** Determine the $\mathrm{pH}$ of the solution resulting when $\pu{100 cm^3}$ of $\pu{0.50 mol dm-3}$ $\ce{CH2ClCOOH}$ is mixed with $\pu{200 cm^3}$ of $\pu{0.10 mol dm-3}$ $\ce{NaOH}$.
**The given solution:**
Concentration of acid: $\frac{0.030}{0.300} = \pu{0.10 mol dm-3}$
Concentration of base/... |
How does the application of Schrodinger's equation to model a particle in a box explain the origin of degeneracy of atomic orbitals? |
We have a kynar coated metal roof that was primed with an acrylic primer and then coated with a dark blue acrylic elastomeric paint. It was coated during spring with moderate weather. The roof surface was dry. Within a few days the coating blistered severely. The blisters were cut out; only the coating was delaminate... |
Oxidation numbers are fictitious charges that pretend the entire molecule is an ion i.e. it artificially localizes electrons onto atoms within a single molecule. In a redox reaction, we find that an oxidation state of one molecule changes compared to a different molecule. Does this mean an *actual* electron was transfe... |
Does a change in oxidation number in a redox reaction mean that an actual electron transfer occured? |
How to run electrochemical tests on Microorganism (bacteria in a medium)? |
Here is where I'm at so far with trying to answer this question:
Is the particle in a box concept analogous to an electron in an orbital? If so, can we apply the equation for the allowed energies of a particle in a box ($E = hn^2/(8mL^2)$), to the allowed energies of electrons in orbitals. If so, are the orbitals de... |
Is the particle in a box concept analogous to an electron in an orbital? If so, can we apply the equation for the allowed energies of a particle in a box
$$E = \frac{hn^2}{8mL^2}$$
to the allowed energies of electrons in orbitals? Are the orbitals degenerate because this equation only includes the quantum number ... |
How does the application of Schrödinger equation to model a particle in a box explain the origin of degeneracy of atomic orbitals? |
Is the particle in a box concept analogous to an electron in an orbital? If so, can we apply the equation for the allowed energies of a particle in a box
$$E = \frac{h^2n^2}{8mL^2}$$
to the allowed energies of electrons in orbitals? Are the orbitals degenerate because this equation only includes the quantum numbe... |
> Is the particle in a box concept analogous to an electron in an orbital?
No, but there is an analogy to the $\pi$ systems of dye molecules, and (for the 3D box) to the band structure of nanodots. Some physical chemistry courses have a lab that explore this relationship, e.g. at [Saarland university][1] (sorry, in ... |
> 1. How would you deal with a user who produced a steady stream of valuable answers, but tends to generate a large number of arguments/flags from comments?
I would put the user on a 30-day performance improvement plan (PIP) and evaluate the trend of behavior during that time. If the behavior has improved, the user ... |
I already did a questionnaire in 2016. Why do I have to do it again?
> 1. How would you deal with a user who produced a steady stream of valuable answers, but tends to generate a large number of arguments/flags from comments?
Answer1hereAnswer 1 here
> 2. How would you handle a situation where another mod clos... |
Almost all Alkali metals and Alkaline Earth metals react with air to form their respective oxides, but why does only Magnesium forms a protective oxide layer? What properties of magnesium oxide allow it to form a layer? |
Why do only some metals make protective oxide layers? |
[![enter image description here][1]][1]
It is a 1H NMR and I think the signal near 3,61 ppm is the CH2 group next to the hydroxy group. But which signal is the Hydroxy group and which protons are in the multiplett?
[1]: https://i.stack.imgur.com/COPyA.jpg |
Does anyone know what molecule this is? I have the assumption that it may be 3methyl1butanol. Can anyone help and tell me the solution? |
[![enter image description here][1]][1]
It is a $\ce{^1H}$-NMR spectrum and I think the signal near 3,61 ppm is the CH2 group next to the hydroxy group. But which signal is the hydroxy group and which protons are in the multiplet?
[1]: https://i.stack.imgur.com/COPyA.jpg |
Is this the NMR spectrum of 3-methyl-1-butanol? |
Welcome to ChemistrySE.
In short: is the spectrum consistent with 3-methyl-1-butanol? No. The triplet splitting and integral of the signal at 0.86ppm is inconsistent with an isopropyl sidechain. This suggests a methyl group attached to a methylene, CH3-CH2-.
The signal at 3.6ppm has a chemical shift symptomatic ... |
[![enter image description here][1]][1]
For ranking the carbocations in the image above,
I thought of taking the approach that the 1st molecule, the secondary carbocation was the most reactive because it has no electron donating group, then the carbocation with a terminal NH2 because nitrogen has an electron donating... |
### Problem
> Nitrogen $(\gamma = 1.4)$ is expanded isentropically. Its temperature changes from $\pu{620 °F}$ to $\pu{60 °F}.$ Find the pressure ratio.
### Answer
>! $p_1/p_2 = 12.91$
### My approach
$$\pu{620 °F} = (1799/3)~\pu{K}$$
$$\pu{60 °F} = (2597/3)~\pu{K}$$
Using isentropic relation:
$$\... |
[![enter image description here][1]][1]
For ranking the carbocations in the image above,
I thought of taking the approach that the 1st molecule, the secondary carbocation was the most reactive because it has no electron donating group, then the carbocation with a terminal NH2 because nitrogen has an electron donating... |
> Oxidation numbers are fictitious charges that pretend the entire molecule is an ion i.e. it artificially localizes electrons onto atoms within a single molecule.
Sort of. In calculating oxidation numbers we pretend that covalent bonds are ionic. Perhaps it is valid to say we are pretending the entire molecule is a... |
> Oxidation numbers are fictitious charges that pretend the entire molecule is an ion i.e. it artificially localizes electrons onto atoms within a single molecule.
Sort of. In calculating oxidation numbers we pretend that covalent bonds are ionic. Perhaps it is valid to say we are pretending the entire molecule is a... |
Welcome to ChemistrySE.
In short: is the spectrum consistent with 3-methyl-1-butanol? No. The triplet splitting and integral of the signal at 0.86ppm is inconsistent with an isopropyl sidechain. This suggests a methyl group attached to a methylene, $\ce{CH3-CH2 -}$.
The signal at $\pu{3.6 ppm}$ has a chemical sh... |
Welcome to ChemistrySE.
In short: is the spectrum consistent with 3-methyl-1-butanol? No. The triplet splitting and integral of the signal at 0.86ppm is inconsistent with an isopropyl sidechain. This suggests a methyl group attached to a methylene, $\ce{-CH2-CH3}$.
The signal at $\pu{3.6 ppm}$ has a chemical shi... |
İ want to plot a graph of ethanol solution concentration over time .So we know that alcohol evaporates quickly in open air but is there a time when the rate of evaporation mathces that of water and concentration stops decreasing or increasing? İ know surface matters but lets assume surface is totally hydrophobic and do... |
In $S_N1$ reactions, it's known that there are generally two steps, with the first being the R.D.S step involving carbocation formation and the next having a lower activation energy.
Why does the second step require activation energy at all? It's going from being a carbocation to a stable molecule, which will be mor... |
Why can't NAD+ undergo single-electron reduction? |
I know that when hydrogen acts as a cation, it can form H-bonds with the electronegative ions or groups. But, is this also true for anionic hydrogens? Will they form similar bonds, other than the existing ionic bond, with electropositive ions, like the alkali metals and alkalikne earth metals, or maybe some other elect... |
Do hydrides, like NaH or CsH, also form H-bond? |
### Problem
> A sample of uranium fluoride is found to effuses at the rate of $\pu{17.7 mg/h}.$ Under comparable conditions, gaseous iodine effuses at the rate of $\pu{15.0 mg/h}.$ What is the molar mass of the uranium fluoride?
### Answer
>! $\pu{354 g mol^-1}$
### My approach
Perhaps I’m still having i... |
$K_p$ will *not* change with pressure, only with temperature. $Q_p$ will instantaneously increase upon applying the pressure for this reaction (why? see below), and will drive the reaction to reactants to re-achieve equilibrium (decreasing $Q_p$) until $Q_p$ = $K_p$ once again. From a LeChatelier approach, you have mo... |
# Question #
***Why is the increase in covalent radius from $\ce{As}$ to $\ce{Bi}$ not as much as the increase in radius from $\ce{N}$ to $\ce{P}$?***
The following is the radius of Group $15$ elements:
| Element | Covalent Radius (in picometres)|
| -------- | ---------------- |
| **N** | $75$ |
| **P** | $... |
Why is the increase in covalent radius from $\ce{As}$ to $\ce{Bi}$ not as much as the increase in radius from $\ce{N}$ to $\ce{P}$? |
I don't think that any realistic modeling is possible. There are a lot of details which would made such a system chaotic. For the liquid side of the gas/liquid system consider the differences in evaporating from a thin layer in a very large diameter vessel to evaporation from a extremely long tube of the mixture.
F... |
# Question #
***Why is the increase in covalent radius from $\ce{As}$ to $\ce{Bi}$ not as much as the increase in radius from $\ce{N}$ to $\ce{P}$?***
The following is the radius of Group $15$ elements:
$$\begin{array}{|c|c|} \hline
\text{Element} & \text{Covalent Radius (in picometres)} \\ \hline
\ce{N} &... |
The following is the radius of Group $15$ elements:
$$\begin{array}{|c|c|} \hline
\text{Element} & \text{Covalent Radius (in picometres)} \\ \hline
\ce{N} &75 \\ \hline
\ce{P} &110 \\ \hline
\ce{As} &121 \\ \hline
\ce{Sb} &140 \\ \hline
\ce{Bi} &155 \\ \hline
\end{array}$$
Source:
General Properties and ... |
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