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I was going through JD Lee and I found certain contradictory statements.
[![enter image description here][1]][1]
Whereas,
[![enter image description here][2]][2]
[![enter image description here][3]][3]
I'm confused about what the order is. Wikipedia says BeF2 is highly soluble, whereas CaF2 is insoluble. Are t... |
We all are familiar with the standard state as 1 bar pressure and 273 K.The standard state can be any well defined state. You can define it in any way that is convenient for you. There is no universal definition. We may want to choose different references depending on the calculation we are doing, so we can choose diff... |
I'm conducting an organic synthesis involving Stille coupling.
Stille coupling uses Pd2(dba)3 and P(o-tol)3 as catalysts.
Both catalysts dissolves in toluene which is the solvent of my experiment.
I have considered several ways to filter these catalysts (e.g. Celite filtration), and I just noticed there are syringe ... |
Is it possible to filter Stille catalysts using syringe filter? |
I am working on a series of octahedral complexes of the type $\ce{[M(CO)2(CH3)X3]-}$ where $\ce{M} = \ce{Co}, \ce{Rh}, \ce{Ir},$ and $\ce{X}$ is a range of ligands (halide, cyanide, nitrosyl, etc.). Now, the complexes all have either a mirror plane or a $C_2$ axis which makes the **two $\ce{CO}$ ligands equivalent by s... |
(Note: I have only a very basic understanding of quantitative lattice energy calculations: I only know that it is directly proportional to the product of charges on the ions and inversely proportional to the distance b/w cation and anion)
Based upon the direct application of the above facts, lattice energy follows t... |
Does folic acid contain a benzyl or a phenyl group? |
I'm conducting an organic synthesis involving Stille coupling.
Stille coupling uses $\ce{Pd2(dba)3}$ and $\ce{P(o-tol)3}$ as catalysts.
Both catalysts dissolves in toluene which is the solvent of my experiment.
I have considered several ways to filter these catalysts (e.g. Celite filtration), and I just noticed ther... |
>Stability of $\ce{H2^{-}}<\ce{H2^{+}}<\ce{H2}$
Source: Online lecture Etoosindia.
I am more concerned of $\ce{H2^{-}}<\ce{H2^{+}}$.
Does any satisfactory explanation exists (perhaps which can be generalized) for it? That is to add electron in anti-bonding molecular orbital more difficult than removing electr... |
Can anybody prove that any molecule with an axis of improper rotation is nonchiral? I still do not understand why this is so, any proper mathematical proof or visualisation of a generalised molecule would be appreciated! |
Subset of: https://chemistry.stackexchange.com/q/4517/108386
>Stability of $\ce{H2^{-}}<\ce{H2^{+}}<\ce{H2}$
>Stability of $\ce{N2^{-}}<\ce{N2^{+}}<\ce{N2}$
Source: Online lecture Etoosindia.
I am more concerned of $\ce{H2^{-}}<\ce{H2^{+}}$.
Does any satisfactory explanation exists (perhaps which can be... |
It is well-known that for electrophilic addition across an alkene, the reactivity increases when intermediate carbocation is more stable (eg. addition of $\ce{HBr}$ or acid-catalyzed addition of $\ce{H2O}$) i.e. when the electron density on carbon atom is more.
For nucleophilic addition on a carbonyl group the react... |
So I was learning about the periodic table where I came across the topic of ionization energy. As a general trend the Ionization energy decreases as we move down a group with a few exceptions such as copper having a greater value of Ionization energy than silver and a few more examples. But on going through the reactiv... |
Why does an improper rotation axis preclude chirality? |
Apparently the entropy change of a system can be found by
$$dS=\frac{\delta q_{rev}}{T}$$
I am slightly confused about this because I have seen this being used when the temperature of the system and the surroundings are not the same. However for the heat exchange to be reversible between the system and surroundi... |
All above answers are correct but I want to add a very rare exception and tell me in comments if I am incorrect (I am interested in that too!).
According to molecular orbital theory molecular orbital diagram of $\ce{B2}$ is
[![enter image description here][1]][1]
Clearly $\ce{B2}$ forms 1 $\pi$-bond without an... |
I came across this on [Wikipedia](https://en.wikipedia.org/wiki/Reducing_sugar#Aldoses_and_ketoses):
> Many disaccharides, like *cellobiose, lactose* and *maltose*, also have a reducing form, as one of the two units may have an open-chain form with an aldehyde group. However, *sucrose* and *trehalose*, in which the... |
Apparently the entropy change of a system can be found by
$$\mathrm dS=\frac{\mathrm\delta q_\mathrm{rev}}T$$
I am slightly confused about this because I have seen this being used when the temperature of the system and the surroundings are not the same. However for the heat exchange to be reversible between the ... |
What would happen if the alpha particles directly hit the electrons in the gold foil in RUTHERFORD'S EXPERIMENT ? |
>Does folic acid contain a benzyl or a phenyl group?
This is the question asked in the title. At the first glance to the structure, one would say folic acid consists of phenyl function but not benzyl function because question did not define what is the phenyl group. In reality, phenyl group $(\ce{Ph})$ is $\ce{C6H5}... |
What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? |
What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment? |
Most producers/suppliers have recommendations for concentration ranges of their products. If you can´t get it directly, it is often possible to find the information on their websites (e.g. Schülke or BASF).
The ranges are typically around 0,1% - 0,5%, but different products are often mixtures of different preservativ... |
>Does folic acid contain a benzyl or a phenyl group?
This is the question asked in the title. At the first glance to the structure, one would say folic acid consists of phenyl function but not benzyl function because the question did not define what is the phenyl group. In reality, phenyl group $(\ce{Ph})$ is $\ce{C... |
I am actually a pure mathematician, who stumbled over this paper
https://www.sciencedirect.com/science/article/pii/S0006349520303763
and then red some introductions on protein folding, as well as articles on Deepminds progress on the issue.
Assume we are given a protein $p$ in primary structure, that is $p = [... |
To which extent is protein folding conserving subprotein structures? |
In quantum mechanics, quantum chemistry, and condensed matter physics courses, it seems like finding the ground state energy of a Hamiltonian is incredibly important. I can understand why having the ground state wave function (or behaviors of the wave function) could help, but I’m struggling to understand how the groun... |
Significance of the ground state energy in quantum chemistry? |
>Does folic acid contain a benzyl or a phenyl group?
This is the question asked in the title. At the first glance to the structure, one would say folic acid consists of phenyl function but not benzyl function because the question did not define what is the phenyl group. In reality, phenyl group $(\ce{Ph})$ is $\ce{C... |
I am actually a pure mathematician, who stumbled over this paper
https://www.sciencedirect.com/science/article/pii/S0006349520303763
and then red some introductions on protein folding, as well as articles on Deepminds progress on the issue.
Assume we are given a protein $p$ in primary structure, that is $p = [... |
Which has the best yield for calsium sulfate? |
I am actually a pure mathematician, who stumbled over this paper «Protein-Folding Analysis Using Features Obtained by Persistent Homology» by Ichinomiya *et al.* (*Biophys. J*. **118**, 2020, 2926-2937; [link][1]), and then red some introductions on protein folding, as well as articles on Deepminds progress on the issu... |
Let's say you have a reaction that has reached equilibrium. The reaction quotient $Q$ will be equal to the equilibrium constant $K$, and the Gibbs energy of reaction will be zero. Now, you decide to change the standard state (without touching your experiment, which is still at equilibrium). For example, if you are a bi... |
Which method has the highest yield of calcium sulfate? |
So I came across an article called "Giant polarization in high polymers" and I was wondering if there was a reason why these types of polymers haven't found use in capacitors at this point. This being ekaconjugated polymers which can store energy using nomadic polarization. Perhaps the issue is with dielectric loss? ... |
Are ekaconjugated polymers used as dielectrics? If not, why so? |
The protein structural terminology in your question needs some work. For example "protein in primary structure embedded in a plane" - the primary structure is the *sequence* of the protein, and it is not clear how that would be embedded in the plane. Perhaps you mean embedding the graph corresponding to the atomic stru... |
the reaction of $\ce{FeCl3}$ with $\ce{CH3COO-}$
is
$\ce{3Fe^{+3} +6CH3COO- +H2O<=> [Fe3(OH)2(CH3COO)6]^{+} +2H^{+}}$
Recently I read that soln of $\ce{FeCl3}$ hydrolyses very quickly to form $\ce{Fe(OH)3 +3H^{+}}$
as described in given equilibrium.
$\ce{FeCl3(aq) +3H2O <=> Fe(OH)3(s) +3H^{+}}$ ,............ |
the reaction of $\ce{FeCl3}$ with $\ce{CH3COO-}$
is
$\ce{3Fe^{+3} +6CH3COO- +H2O<=> [Fe3(OH)2(CH3COO)6]^{+} +2H^{+}}$
Recently I read that soln of $\ce{FeCl3}$ hydrolyses very quickly to form $\ce{Fe(OH)3 +3H^{+}}$
as described in given equilibrium.
$\ce{FeCl3(aq) +3H2O <=> Fe(OH)3(s) +3H^{+}}$ ,............ |
What would be the major product between 4-chloro-pentanal and lialh4?
After the reduction of the aldehyde, would the hydroxyl group formed at carbon 1 attack carbon 4 causing cyclization to occur?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/dAte4.png |
What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment?
Would it get ionized or is there no probability of such a thing happening ? |
I was going through JD Lee and I found certain contradictory statements.
[First][1]:
>With most compounds, on descending the group, the hydration energy decreases more rapidly than the lattice energy: hence the compounds become less soluble as the metal gets larger. However, with fluorides and hydroxides the lat... |
What is the solubility trend of alkaline earth metal fluorides? |
What would be the major product between 4-chloro-pentanal and $\ce{LiAlH4}$?
After the reduction of the aldehyde, would the hydroxyl group formed at carbon 1 attack carbon 4 causing cyclization to occur?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/dAte4.png |
Hi im a kinda beginer in Basic Chemistry and there was this exercise that i needed some directions with
The exercise goes like this :
A water solution is prepared by mixing 200 g of a ethylene
glycol (ethane-1,2-diol)($C_2H_6O_2$) solution (20%wt) with 500g of glycerol
(propane-1,2,3-triol)($C_3H_8O_3$) solution ... |
What would be the major product between 4-chloropentanal and $\ce{LiAlH4}$?
After the reduction of the aldehyde, would the hydroxyl group formed at $\ce{C-1}$ attack $\ce{C-4}$ causing cyclization to occur?
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/dAte4.png |
What is the major product in the reaction between 4-chloropentanal and lithium aluminium hydride? |
The reaction of $\ce{FeCl3}$ with $\ce{CH3COO-}$
is:
$$\ce{3Fe^3+ +6CH3COO- +H2O<=> [Fe3(OH)2(CH3COO)6]+ +2H+}$$
Recently I read that soln of $\ce{FeCl3}$ hydrolyses very quickly to form $\ce{Fe(OH)3 +3H+}$
as described in given equilibrium.
$$\ce{FeCl3_{(aq)} +3H2O <=> Fe(OH)3_{(s)} +3H+}\tag{1}\label{eq... |
Why is it advised to use neutral ferric chloride solution while performing confirmatory test for acetate ions? |
> A water solution is prepared by mixing $\pu{200 g}$ of a ethylene glycol (ethan-1,2-diol)($\ce{C2H6O2}$) solution(20% by weight) with 500g of glycerol (propan-1,2,3-triol)($\ce{C3H8O3}$) solution(15% by weight). Calculate the freezing temperature and the osmotic pressure at 25°C knowing that the density of the prepar... |
The reaction of $\ce{FeCl3}$ with $\ce{CH3COO-}$ is
$$\ce{3Fe^{+3} +6CH3COO- +H2O<=> [Fe3(OH)2(CH3COO)6]^{+} +2H^{+}}$$
Recently I read that a solution of $\ce{FeCl3}$ hydrolyses very quickly to form $\ce{Fe(OH)3 +3H^{+}}$ as described by the following equilibrium:
$$\ce{FeCl3(aq) +3H2O <=> Fe(OH)3(s) +3H^{+... |
How does one go about determining the equivalents of OH- needed for the titration of a weak acid. For example here is the titration curve for Aspartate
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/KEpJE.png
Why is the equivalents for pKa1 = 0.5 why not 0.75, why not 0.80? How was ... |
The **Biuret Test** is a chemical assay that detects the presence of proteins in a sample. The test is not named after any famous scientist, but after an urea dimer called *biuret* $(\ce{H2NC(O)NHC(O)NH})$. However, funny thing is *biuret* is not a part of the test at all. The test is called **Biuret Test** because *bi... |
How does one go about determining the equivalents of $\ce{OH-}$ needed for the titration of a weak acid. For example here is the titration curve for Aspartate:
[![The titration curve for Aspartate][1]][1]
[1]: https://i.stack.imgur.com/KEpJE.png
Why is the equivalents for $\mathrm{p}K_\mathrm{a1} = 0.5$? Why... |
> A water solution is prepared by mixing $\pu{200 g}$ of a ethylene glycol (ethan-1,2-diol; $\ce{C2H6O2}$) solution (20% by weight) with $\pu{500 g}$ of glycerol (propan-1,2,3-triol; $\ce{C3H8O3}$) solution (15% by weight). Calculate the freezing temperature and the osmotic pressure at $\pu{25 ^\circ C}$ knowing that t... |
What would be the major product between 4-chloropentanal and $\ce{LiAlH4}$?
After the reduction of the aldehyde, would the hydroxyl group formed at $\ce{C-1}$ attack $\ce{C-4}$ causing cyclization to occur?
[![Structure of 4-chloropentanal][1]][1]
[1]: https://i.stack.imgur.com/3MZhS.png
|
I have read about this topic in both of my chemistry and physics books but not them exactly pointed out the significance of the significant figures.
Then I search the internet for the same and I got two answers. Some people are saying that it is to denote the accuracy and others are saying that it is to denote the p... |
What's the purpose of significant figures in measurements? |
How do I compare the bond angle between $\ce{O_3}$ and $\ce{NO_2^-}$ ?
I've studied how to compare the bond angle when normal covalent bonds are present and the electrons are shared in the bond and so the concept of electron repulsion is used to judge the bond angle. But what about the case when one of the bonds is ... |
How do I compare the bond angle between $\ce{O_3}$ and $\ce{NO_2^-}$ ?
I've studied how to compare the bond angle when normal covalent bonds are present where the electrons are shared in the bond and so the concept of electron repulsion is used to judge the bond angle. But what about the case when one of the bonds i... |
This problem given in my book confused me a little bit:
>when an excess of ethyl alcohol vapour is passed over heated alumina ($250^\circ$C), the main product is?
I read that this reaction gives an ether( here, diethyl ether) at relatively lower temperature than when it gives an alkene(here, ethene).
Th... |
When does reaction of alcohol with alumina give ethers and when an alkene? |
Why is the bond angle of $\ce{SF_2 (98.05^\circ) > SH_2 (92.11^\circ)}$
Isn't this contradicting to bents rule or otherwise electron repulsion rule ? Flourine is more electronegative and hence it should have bonds with higher p character than those which Hydrogen will form. Which means F-S-F bond angle should be sm... |
I was reading some books on propulsion and combustion, and the author suggests the following exercise :
the heat released of the reaction $H_2 + \frac{1}{2}O_2 \rightarrow H_2O_{(g)} $ at constant-temperature and constant-pressure is $q_{_{(P,T)}} = 57.8\ kcal$
**What is the heat released $q_{_{(\rho,T)}}$ of t... |
I read somewhere that Friedel Craft's alkylation of naphthalene by alkyl halides (having more than 2 carbons) occurs at 2-position. On the other hand, with smaller halides, it occurs at the 1-position. Does it have something to do with steric factors or is there some other reason? |
What are the products formed when naphthalene is subjected to Friedel Craft's alkylation using alkyl halides in presence of a Lewis acid catalyst? |
I read that Friedel Craft's alkylation of naphthalene by alkyl halides having more than 2 carbons occurs at 2-position. On the other hand, with smaller halides, it occurs at the 1-position.
Does it have something to do with steric factors or is there some other reason? |
Is regioselectivity affected by steric factors during alkylation of naphthalene? |
Is it compulsory to have the coefficients of a balanced chemical equation in the simplest ratio? |
I have recently read that the number of sterioisomers in a compound having **n** chiral centres is $2^n$. (That is, if no meso form is present)
The below question asks for the number of sterioisomers in the product obtained and the product obtained has 3 chiral centres, so it should be $2^3$ = 8, but the answer give... |
I have recently read that the number of sterioisomers in a compound having **n** chiral centres is $2^n$. (That is, if no meso form is present)
The below question asks for the number of sterioisomers in the product obtained and the product obtained has 3 chiral centres, so it should be $2^3$ = 8, but the answer give... |
Why is the bond angle of $\ce{SF_2 (98.05^\circ) > SH_2 (92.11^\circ)}$
Isn't this contradicting to bents rule or otherwise electron repulsion rule ? Flourine is more electronegative and hence it should have bonds with higher $\mathrm p$ character than those which Hydrogen will form. Which means $\ce{F-S-F}$ bond a... |
Why is the bond angle of sulphur diflouride greater than that of hydrogen sulphide? |
>Is there a relation between heat released at constant pressure and temperature and heat released at constant density and temperature?
I was reading some books on propulsion and combustion, and the author suggests the following exercise:
the heat released of the reaction $\ce{H_2 + 1/2O_2 -> H_2O_{(g)} }$ at con... |
Why is the bond angle of $\ce{SF_2 (98.05^\circ) > SH_2 (92.11^\circ)}$?
Isn't this contradicting Bent's rule or otherwise electron repulsion rule ? Fluorine is more electronegative and hence it should have bonds with higher $\mathrm p$ character than those which hydrogen will form. Which means $\ce{F-S-F}$ bond ang... |
Why is the bond angle of sulphur difluoride greater than that of hydrogen sulphide? |
Can someone give me examples of Hydrogen's ionic bonding? |
The order for the solubility of *isomeric* alcohols in a book was given as:
*Primary alcohol >Secondary alcohol >Tertiary alcohol*
After this I found a question:
>(1) Which is more soluble in water?
>(a) 3-ethyl-3-hexanol
>(b) 2-octanol
Ans: *(a)*
The reason was that (a) has a more compact al... |
What is the solubility order of isomeric alcohols in water? |
What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment?
Would it get ionized or is there no probability of such a thing happening ?
IS IT POSSIBLE ? |
I have HCl and NaOH titration and in the equivalence point I get pH=8.6, but the pH must be 7 in this kind of titration, then why this happen?, does it possible that I don't take enough point in the area of the equivalence point and this makes the pH>7? |
could the pH in the equivalence point of strong acid and strong base titration be greater than 7? |
How to make plasma in microwave (without grapes please)? |
What would happen if the alpha particles directly hit the electrons in the gold foil in Rutherford's experiment?
Would it get ionized or is there no probability of such a thing happening ? |
I have $\ce{HCl}$ and $\ce{NaOH}$ titration and in the equivalence point I get $\mathrm{pH} = 8.6$, but the $\mathrm{pH}$ must be $7$ in this kind of titration, then why this happen? Does it possible that I don't take enough point in the area of the equivalence point and this makes the $\mathrm{pH} \gt 7$? |
Could the pH in the equivalence point of strong acid and strong base titration be greater than 7? |
Is Thermoplastic Rubber Food/Pet Safe? Confusions between TPR and TPE |
I have HCl and NaOH titration and in the equivalence point I get pH=8.6, but the pH must be 7 in this kind of titration, then why this happen? Does it possible that I don't take enough points in the area of the equivalence point and this makes the pH>7? |
Could the pH in the equivalence point of strong acid and strong base titration be greater than 7? |
**Run the following demos with a cup of water in the microwave, and the test object on an inexpensive glass or ceramic plate, to reduce the risk of damage to the microwave itself. Even with care, expect plates to crack, and there is still possibility of damage to the oven.** You might also want to remove or cover the l... |
[Material food contact safety rating][1] is not a simple topic. Depending on how a product is made, it may be approved or not. BPA and other plasticizers are only one component.
See the particular manufacturer's [NSF, FDA or USDA rating][2]. Can they substantiate the claims for thermoplastic elastomer (TPE) or therm... |
I have a very basic understanding of quantitative lattice energy calculations: I only know that the lattice energy is directly proportional to the product of charges on the ions and inversely proportional to the distance between cation and anion.
Based upon the direct application of the above facts, lattice energy f... |
Do superoxide salts of heavier alkali metals contradict the principle that lattice energy depends inversely on cation-anion distance? |
How can we make metal coating or oil paint by the use of unsaturated polyester resin and its suitable solvent, plus some pigments only if really required? |
Please see the problem in [this link][1]. I understand the explanation in (c), but it appears to me, that accepting that would contradict the answers to parts (a), (b), and (c).
Is the reason for part (a) because the first molecule does not have resonance, and for (b) the $\ce{F3C-I}$ molecule has a larger inducti... |
How to rationalise differences in halogen bonding? |
When metals are electroplated unto surfaces, there are a myriad of forces at play. To set a clear example, if one were to electroplate a magnet with a diamagnetic metal such as bismuth, there will be a certain amount of repulsion from the substrate from the surface. Hence, how could one check how much distance there wi... |
How can the difference between surface energy and electrostatic repulsion be calculated in electroplating? |
How to determine which gas liquifies first when cooled from high T, based on formula and critical temperature? |
I hope to clear up some confusion I have about acid-base reactions in aqueous solution.
Based on the Bronsted-Lowry definition of acids, I know acids donate protons. In water, a strong acid should react completely with water to form hydronium and some anion. For example, HCl + H2O -> H3O+ + Cl-.
However, my confu... |
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