instruction stringlengths 15 21.8k |
|---|
Is there any mechanism avalable for reduction of alkyl azides to amines.
One of the reactions are conversion by Na in ethanol or by LiAlH4.
But how do these procede?
LiAlH4 will produce a hydride ion-which attacks where? |
What color is solid methane? |
I am not seing tBu listed as alcohol protection group in all of these places:
- https://en.wikipedia.org/wiki/Protecting_group#Alcohol_protecting_groups
- http://www.synarchive.com/protecting-group/
- http://www.organic-reaction.com/organic-synthesis/protecting-groups/ether/
On the other hand it seems to be ... |
Why is tert-Butyl (tBu) often not listed as protecting group for alcohol? |
Is there any mechanism avalable for reduction of alkyl azides to amines.
One of the reactions are conversion by $\ce{Na}$ in ethanol or by $\ce{LiAlH4}$.
But how do these procede?
$\ce{LiAlH4}$ will produce a hydride ion which attacks where? |
I am studying Chemistry by Zumdahl and Zumdahl (9th edition) and I have come across a question in Chapter 11 that I can't figure out the explanation for:
*Liquid A has vapor pressure* x *, and liquid B has vapor pressure* y *. What is the mole fraction of the liquid mixture if the vapor above the solution is 30% A b... |
I have 2 questions in mind:
1) What is the structure of the superoxides? More specifically, what is the structure of KO$_2$?
2) What is the structure of and dipole moment for XeF$_6$? |
Nitrogen has no d-orbitals. Yet, it forms compounds where its oxidation state is +5, like in Nitric Acid. How? |
How can nitrogen achieve +5 oxidation state? |
Nitrogen has no available d-orbitals. Yet, it forms compounds where its oxidation state is +5, like in nitric acid. How? |
Is there any mechanism available for reduction of alkyl azides to amines.
One of the reactions is conversion by $\ce{Na}$ in ethanol or by $\ce{LiAlH4}$.
But how do these proceed?
$\ce{LiAlH4}$ will produce a hydride ion which attacks where? |
I have recently studied superposition of states (also the famous Schrodinger's cat), measurement problem, decoherence & so on. I then read the resonance concept from Atkins' Physical Chemistry where it was written as:
>It is the superposition of **wavefunctions** representing different electron distributions in the ... |
So I was having trouble drawing the Lewis structure for $\ce{NCO^-}$. I found this image online:
![enter image description here][1]
But why number one and not the number two? Why does carbon prefer to have a triple bond with nitrogen, rather than have a double bond with nitrogen and a double bond with oxygen?
... |
I was having trouble drawing the Lewis structure for $\ce{NCO^-}$. I found this image online:
![enter image description here][1]
But why is structure number one preferred over structureumber two? Why does carbon prefer to have a triple bond with nitrogen, rather than have a double bond with nitrogen and a double ... |
I was having trouble drawing the Lewis structure for $\ce{NCO^-}$. I found this image online:
![enter image description here][1]
But why is structure number one preferred over structure number two? Why does carbon prefer to have a triple bond with nitrogen, rather than have a double bond with nitrogen and a doubl... |
> What is the maximum number of double bonds a carbon atom can make?
Well, carbon has $4$ valence electrons so... it needs $4$ more to fulfill the octet rule right?
If a double bond yields $4$ electrons, does it mean that he carbon atom can make only one double bond?
**OR** does it mean it can create up to TWO... |
By clarifying butter, e.g. by melting butter and filtering it, we rid ourselves of most of the protein in the butter, and are left with mostly fat. However, the separation of protein and fat is not complete. Some people cannot eat milk proteins due to allergic reactions, and cannot therefore use unrefined butter in the... |
This question dates back to a time where I used to watch something called The Curiosity Show... Kinda like Bill Nye the Science Guy's show. I just can't recall the answer to this so I'm hoping that someone could shed some light.
I have two glasses of equal size and volume, with equivalent volumes of orange juice and c... |
Consider the following reaction.
2 HF(aq) + Ca(OH)2(aq) -> CaF2(s) + 2 H2O(l)
The reaction produced a fairly insoluble salt.
Assume that this reaction proceeds entirely to completion as the acid and bases were initially in equimolar quantities with respect to their stoichiometry.
What is the result... |
Neutralization reaction with insoluble salt (weak acid, strong base)? |
Consider the following reaction.
2 HF(aq) + Ca(OH)2(aq) -> CaF2(s) + 2 H2O(l)
The reaction produced a fairly insoluble salt.
Assume that this reaction proceeds entirely to completion as the acid and bases were initially in equimolar quantities with respect to their stoichiometry.
What is the result... |
A classic test for protein is [Biuret solution][1], using readily available reagents: sodium hydroxide, copper sulfate and potassium sodium tartrate (Rochelle salt). The test is not specific for milk protein, but what *other* protein would be in pure butter?
Use caution with the chemicals -- the first listed is qui... |
This isn't a homework question so please put pitchforks down. Let's look at question c
![enter image description here][1]
[1]: https://i.stack.imgur.com/8t8FR.png
So, I'm abit confused with what's happening. It seems that water is acting as an acid in this reaction, and donating protons to the ion. Can som... |
Let's look at question c
![enter image description here][1]
[1]: https://i.stack.imgur.com/8t8FR.png
So, I'm a bit confused with what's happening. It seems that water is acting as an acid in this reaction, and donating protons to the ion. Can someone just elaborate on this whole process please because I'm ... |
Why does hydrogen phosphate act as a base? |
I have 2 questions in mind:
1) What is the structure of the superoxides? More specifically, what is the structure of $\ce{KO_2}$?
2) What is the structure of and dipole moment for $\ce{XeF_6}$? |
What are the structures of potassium superoxide and xenon hexafluoride? |
Why does iodine have different colors in different media? |
A student forgot to add the reaction mixture to the round bottomed flask at 27°C but instead he placed the flask on the flame. After a lapse of time he realised his mistake and using a pyrometer he found the temperature of the flask was 477°C. What fraction of air would have been expelled out? |
> A student forgot to add the reaction mixture to the round bottomed
> flask at 27°C but instead he placed the flask on the flame. After a
> lapse of time he realised his mistake and using a pyrometer he found
> the temperature of the flask was 477°C. What fraction of air would
> have been expelled out? |
> A student forgot to add the reaction mixture to the round bottomed
> flask at 27°C but instead he placed the flask on the flame. After a
> lapse of time he realised his mistake and using a pyrometer he found
> the temperature of the flask was 477°C. What fraction of air would
> have been expelled out? |
> A student forgot to add the reaction mixture to the round bottomed
> flask at 27°C but instead he placed the flask on the flame. After a
> lapse of time he realised his mistake and using a pyrometer he found
> the temperature of the flask was 477°C. What fraction of air would
> have been expelled out? by solving ... |
> A student forgot to add the reaction mixture to the round bottomed
> flask at 27°C but instead he placed the flask on the flame. After a
> lapse of time he realised his mistake and using a pyrometer he found
> the temperature of the flask was 477°C. What fraction of air would
> have been expelled out?
by solv... |
Maltose has a 1,4 glycosidic linkage between two molecules of α-D-Glucopyranose.
My textbook suggests the final name of maltose as
> 4-O-(α-D-Glucopyranosyl)-D-glucopyranose
* I wanted to know what does "4-O-" stands for ?
I dont think so it provides information about the atoms which are linked and more... |
According to my book, equivalent weight is defined as the ‘number of parts by weight’ of an element that interacts with 1.008 parts by weight of hydrogen. It is dimensionless while gram equivalent weight has gram as units. But in https://en.wikipedia.org/wiki/Equivalent_weight, equivalent weight and gram equivalent wei... |
This question dates back to a time where I used to watch something called The Curiosity Show... Kinda like Bill Nye the Science Guy's show. I just can't recall the answer to this so I'm hoping that someone could shed some light.
I have two glasses of equal size and volume, with equivalent volumes of orange juice and... |
> A student forgot to add the reaction mixture to the round bottomed flask at 27 °C but instead he placed the flask on the flame. After a lapse of time he realised his mistake and using a pyrometer he found the temperature of the flask was 477 °C. What fraction of air would have been expelled out?
By solving $$\fra... |
What fraction of air does elapse upon heating an ampty flask? |
What fraction of air does elapse upon heating an empty flask? |
Why is the maximum theoretical efficiency of Ar engine higher than that of Nitrogen engine? On a molecular level.
For an Otto Cycle
- Eff ≤ (1-r(^1-γ))
- γ=Cp/Cv
- r=v1/v2
Sys. Fluid
- Nitrogen, γ=1.4, r=10, eff(max)=60.2%
- Argon, γ=1.67, r=10, eff(max)=78.5% |
Consider the following reaction.
$\ce{2 HF(aq) + Ca(OH)2(aq) -> CaF2(s) + 2 H2O(l)}$
The reaction produced a fairly insoluble salt.
Assume that this reaction proceeds entirely to completion as the acid and bases were initially in equimolar quantities with respect to their stoichiometry.
What is the resultin... |
![enter image description here][1]
$$\frac{\log{10}~pg}{ml}$$
I do not understand the scale. How do I convert this to a standard concentration (without the logs)?
[1]: https://i.stack.imgur.com/MfqyS.png |
![enter image description here][1]
$$\log_{10}~\mathrm{pg}/\mathrm{ml}$$
I do not understand the scale. How do I convert this to a standard concentration (without the logs)?
[1]: https://i.stack.imgur.com/MfqyS.png |
Why is the maximum theoretical efficiency of Ar engine higher than that of Nitrogen engine? On a molecular level.
For an Otto Cycle
- $\mathrm{Eff} \le\left(1-r^{1-\gamma}\right)$
- $\gamma=\dfrac{C_p}{C_v}$
- $r=\dfrac{v_1}{v_2}$
Sys. Fluid
- Nitrogen, $\gamma=1.4,\ r=10,\ \mathrm{eff(max)}=60.2%$
... |
You have been given the first, second and third ionization energies of an element as 7eV, 12.5eV and 42.5eV, respectively. How do you find the most stable oxidation state (or charge on the resultant ion) of that element? Thanks in advance? |
Can anyone tell me the difference of aggregates and clusters from the molecular point of view? Thank you so much. |
Difference of aggregate and cluster? |
I do not mean at the same time, of course, but I mean it appears from an overview of the common charges formed from ionizing various elements that each element forms one or more of either positive or negative ions, but they never have the opposite charge. For example Fe may have +4 or +3, but never -anything.
**Howev... |
Why do atoms form either a positive or a negative charge, but not both? |
According to my textbook, fluorine has a pretty high (compared to elements like sodium) first ionization energy. *But why does it have such a high requirement to ionize?* After all, it actively seeks out atoms to bond with, even tearing through already existing bonds in its drive to do so.
I would expect that fluor... |
Does ionization energy have anything to do with how reactive an element is? |
What property of lithium makes them forms the nitride, lithium nitride Li3N whereas the other group 1 elements forms the azide, like sodium azide and potassium azide - NaN3 and KN3 respectively?
Does lithium azide exist? If so, what is its structure? |
I was researching about electronegativity when I looked up what a graph of electronegativity within the periodic table is. And, [this][1] appeared. I scanned it, matching up everything I knew about the elements up to that table. Yep, Group 1 is all light colored; yea, the nonmetals are all really dark blue culminating ... |
Why are noble metals more electronegative then most metals? |
Actually, in theory almost all of the elements can be found with both oxidation positive and negative oxidation numbers, it's just a matter of finding a system with the proper reagents and conditions to force it. If you isolate chemical species which have a *very* strong tendency of displaying some specific behaviour (... |
You are correct in saying that it is possible but not common. This comes about as a consequence of the effective nuclear charge on the atom or Z. eff, and the size of the atom. Z effective if you are not familiar is a concept usually touched upon in chem 2 as a periodic trend. It is a measure of the charge felt by the ... |
Stereoselective enolate formation with different bases: Does the addition of a base NR3 to a ketone affords the cis or the trans enolate? |
You are correct in saying that it is possible but not common. This comes about as a consequence of the effective nuclear charge on the atom or Z. eff, and the size of the atom. Z effective if you are not familiar is a concept usually touched upon in chem 2 as a periodic trend. It is a measure of the charge felt by the ... |
What property of lithium makes them forms the nitride, lithium nitride $\ce{Li3N}$ whereas the other group 1 elements forms the azide, like sodium azide and potassium azide - $\ce{NaN3}$ and $\ce{KN3}$ respectively?
Does lithium azide exist? If so, what is its structure? |
Actually, in theory almost all of the elements can be found with both oxidation positive and negative oxidation numbers, it's just a matter of finding a system with the proper reagents and conditions to force it. If you isolate chemical species which have a *very* strong tendency of displaying some specific behaviour (... |
Titanium and Tantalum are quite nonreactive, so using 'safe' acids, such as diluted acetic acid won't make any difference. That's why using strong acids such as (sometimes has to be hot ) sulfuric acid will do it. If you are looking for not having to work with sulfuric acid, you could always use hydrogen iodide : that ... |
I'm currently downloading .cif files from various online databases and using openbabel to convert the fractional coordinates that are in the .cif files into .xyz files. The typical output will look something like this:
5
Spinel
Mg 1.01054 1.01054 1.01054
Al 1.01054 1.01... |
I'm currently downloading .cif files from various online databases and using openbabel to convert the fractional coordinates that are in the .cif files into .xyz files. The typical output will look something like this:
5
Spinel
\begin{array}{c|c c c}
\ce{Mg} & 1.01054 & 1.01054 & 1.01054\\\h... |
Does the addition of tert-butanolate to 3-pentanone give the cis or trans enolate? |
I'm wondering if the addition of a base of type $\ce{NR_3}$ (R: alkyl) to a ketone (e.g. 3-Pentanone or 4-Heptanone) results in the cis or trans-enolate.
I didn't find any internet page which studies this question, therefore I'd like to ask here about four cases:
a) $\ce{NMe_3}$ (small)
b) $\ce{NMeEt_2}$ (med... |
My book says - "NaCl shows metal excess defect, which results into the formation of an F-center in the crystal. This F-center is responsible for the yellow color of NaCl."
My question is, how does an F-center provide color to the solid? |
Does the addition of base to 3-pentanone give the cis or trans enolate? |
Actually, in theory almost all of the elements can be found with both oxidation positive and negative oxidation numbers, it's just a matter of finding a system with the proper reagents and conditions to force it. If you isolate chemical species which have a *very* strong tendency of displaying some specific behaviour (... |
However, because the number of atoms of sodium and chlorine in table salt is not the same, but a cubic crystal salt is neutral? |
**Question:**
You have been given the first, second and third ionization energies of an element as 7eV, 12.5eV and 42.5eV, respectively. How do you find the most stable oxidation state (or charge on the resultant ion) of that element?
I think that the element has to ionize with oxygen to reach a certain oxidation... |
In molecular orbitals diagram, sigma ($\sigma$) and pi ($\pi$) symbols are used. What do these symbols really mean? |
**Background**:
I use Sodium persulfate to etch a copper board to manufacture home made Printed Circuit Board (PCB).
On the etching powder's plastic, it is written that:
> 1.5-2dl of etch powder in 1 L of hot water or corresponding volumes
So I add 2 cup powder for 10 cup hot water. In the first time usa... |
Humans typically achieve combustion by starting a chemical reaction of a fuel (often a carbon $\ce{C}$ containing fluid like methan $\ce{CH4}$), which is is brought into an an oxidizer ($\ce{O}$ containing gas, like air). For exmaple, when you turn on a lighter.
>What would happen if the situation is turned around?... |
Actually, in theory almost all of the elements can be found with both positive and negative oxidation numbers: it's just a matter of finding a system with the proper reagents and conditions to force it. If you isolate chemical species which have a *very* strong tendency of displaying some specific behaviour (accepting ... |
I was researching about electronegativity when I looked up what a graph of electronegativity within the periodic table is. And, [this][1] appeared. I scanned it, matching up everything I knew about the elements up to that table. Yep, Group 1 is all light colored; yea, the nonmetals are all really dark blue culminating ... |
As a prenote: My answer is somehow speculative because I have no experimental data or reference values of similar reactions used. In other words: The argumentation pathway below might be wrong.
Addition of LDA mostly gives the trans-enolate if a primary alkyl substituent next to the carbonyl group has been used.
... |
According to my textbook, fluorine has a pretty high (compared to elements like sodium) first ionization energy. *But why does it have such a high requirement to ionize?* After all, it actively seeks out atoms to bond with, even tearing through already existing bonds in its drive to do so.
I would expect that fluor... |
First off, I am currently confused about **why** neon [can even be ionized at all.][1] But since it *can* be ionized, this is the energy required to give a mole of neon a charge of +8: `207,390,000` joules!! Or ~0.5 GJ! Giving *one-fifth of a kilogram of neon the maximum charge would be like the energy from **50 armor-... |
Can you in reality give neon a charge of +8? |
Consider this picture of an $\cf{NaCl}$ unit cell:
![NaCl Unit cell][1]
[1]: https://i.stack.imgur.com/HBKGW.gif
It appears to show 14 $\cf{Cl-}$ ions and only 13 $\cf{Na+}$ ions. Given that discrepancy, how is table salt balanced for charge? Why isn't there a charge excess? |
I observed the absorbance on Phenolphthalein in acidic and basic medium, and I know that the absorbances differ due to the number of conjugated double bonds, but I am not sure exactly why this happens. I believe it has something to do with the delocalised electrons, which causes lower energy differences, but I am unabl... |
Relation between number of conjugated double bonds and absorbance? |
There's a reaction occurring at constant $T$ and $P$, and it is in chemical equilibrium. Now by adding infinitesimal quantities of reactants, it is taken to another equilibrium state in a reversible way. During this process, if entropy change is $\Delta S$ and volume change $\Delta V$, $$\Delta U = T \Delta S - P \Delt... |
Is there no irreversible way of moving between two equilibrium states at constant T and P? |
Can I create carbon monoxide gas by just mixing formic acid & sulphuric acid together. Or do they have to be heated? |
Can I create carbon monoxide gas? |
If oxygen has a valency of 2-, 4 of it would result in 8-. But iron doesn't have a (variable) valency of anything that goes with 8-. How? |
How is the oxide of iron Fe3O4 possible? |
If oxygen has a valency of 2-, 4 of it would result in 8-. But iron doesn't have a (variable) valency of anything that goes to 8-. How is $\ce{Fe3O4}$ possible? |
How is the oxide of iron: Fe3O4 possible? |
Noble metals are close to filling both s and d subshells, so there is a certain stability in gaining electrons. Gold atoms form bonds with each other similar in strength to hydrogen bonds and can form stable $Au^-$ salts with hard cations like $Cs^+$. Platinum similarly forms $Pt^{2-}$. There are also relativistic effe... |
Noble metals are close to filling both $s$ and $d$ subshells, so there is a certain stability in gaining electrons. Gold atoms form bonds with each other similar in strength to hydrogen bonds and can form stable $\ce{Au^-}$ salts with hard cations like $\ce{Cs^+}$. Platinum similarly forms $\ce{Pt^{2-}}$. There are als... |
In the preparation of H2SO4 through Contact process, H2SO4 is added to hot sulfur trioxide to form oleum. This oleum is then diluted by adding water to form H2SO4.
H2SO4(l) + SO3(g) → H2S2O7(l)
H2S2O7(l) + H2O(l) → 2 H2SO4(l)
In a preparatory reaction, different reagents are used to obtain the desired product... |
60cm3 of Oxygen was added to 10cm3 of a gaseous unsaturated hydrocarbon. After explosion and cooling to room temperature, the residual gaseous occupied 45cm3. What volume of Carbon Dioxide was formed in the reaction? |
How to find the volume of CO2 formed in the reaction, given volume? |
In the preparation of $\ce{H2SO4}$ through contact process, $\ce{H2SO4}$ is added to hot sulfur trioxide to form oleum. This oleum is then diluted by adding water to form $\ce{H2SO4}$.
$$\ce{H2SO4(l) + SO3(g) → H2S2O7(l)}$$
$$\ce{H2S2O7(l) + H2O(l) → 2 H2SO4(l)}$$
In a preparatory reaction, different reagents... |
What is the hybridization of oxygen in phenol molecule? I assume it is sp3 hybridized because it forms 2 bonds - 1 with benzene, another with hydrogen, as in how oxygen is hybridized in a water molecule - sp3.
Now the problem is, my A - level lecturers insist that it is the p orbital of oxygen that overlaps with the d... |
Can I create carbon monoxide gas by just mixing formic acid and sulphuric acid together. Or do they have to be heated? |
What is the hybridization of oxygen in phenol molecule? I assume it is $sp^3$ hybridized because it forms 2 bonds - 1 with benzene, another with hydrogen, as in how oxygen is hybridized in a water molecule - $sp^3$.
Now the problem is, my A - level lecturers insist that it is the p orbital of oxygen that overlaps with... |
In the preparation of $\ce{H2SO4}$ through the Contact process, $\ce{H2SO4}$ is added to hot sulfur trioxide to form oleum. This oleum is then diluted by adding water to form $\ce{H2SO4}$.
$$\ce{H2SO4(l) + SO3(g) → H2S2O7(l)}$$
$$\ce{H2S2O7(l) + H2O(l) → 2 H2SO4(l)}$$
In a preparatory reaction, different reag... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.