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Why are Andrews' isotherms divided into three fragments at low temperature and low pressure? |
While reading organic texts, I have come across authors referring to "Activation of alkene" what does that mean !? Does it mean to include the alkene in resonance or what else exactly ? |
What does activation of alkene mean? |
While reading organic texts, I have come across authors referring to "Activation of alkene" what does that mean !? Does it mean to include the alkene in resonance or what else exactly ?
<b> Where did I read it ? <b>: While reading about heck reaction: The palladium-catalyzed C-C coupling between aryl halides or viny... |
While reading organic texts, I have come across authors referring to "Activation of alkene" what does that mean !? Does it mean to include the alkene in resonance or what else exactly ?
<b> Where did I read it ? </b>: While reading about heck reaction: The palladium-catalyzed C-C coupling between aryl halides or vin... |
While reading organic texts, I have come across authors referring to "Activation of alkene" what does that mean !? Does it mean to include the alkene in resonance or what else exactly ?
I saw this notation, while reading about Heck reaction:
>The palladium-catalyzed C-C coupling between aryl halides or vinyl ... |
In the conversion of m-chloroanisole to m-anisidine using $NaNH_2$ and liquid $NH_3$, apparently the reason the $NH_2^-$ goes for the meta- position instead of the para position is that in the reaction mechanism for the conversion to m-anisidine, the benzyne intermediate involved has the triple bond closer to the $-OCH... |
I read in a page that ionisation is an irreversible process. But, as equilibrium is always reversible would that mean equilibrium does not involve ionisation process.
And than dissociation is a reversible process therefore only dissociation process is seen in ionic equilibrium.
Now if the above statement is corr... |
Is ionisation an equilibrium process? |
In the conversion of m-chloroanisole to m-anisidine using $\ce{NaNH2}$ and liquid $\ce{NH3}$, apparently the reason the $\ce{NH2-}$ goes for the meta- position instead of the para position is that, in the reaction mechanism for the conversion to m-anisidine, the benzyne intermediate involved has the triple bond closer ... |
How to convert cell diagram to a chemical equation? |
Why don't we take the effects of stirring and shaking on the rates of chemical reactions? While studying chemical kinetics, I've seen that the rates depend on the concentrations of various species, temperature, pressure, etc. But I've never seen an equation taking into account the mechanical stirring, shaking and geome... |
When you fill up a balloon about a quarter way with liquefied butane fuel and let it sit at room temperature it will turn into gas. But why does the gas weigh the same as the liquified butane?
> The liquefied butane liquid weighs just about as much as water. |
When you fill up a balloon about a quarter way with liquefied butane fuel and let it sit at room temperature it will turn into gas. But why does the gas weigh the same as the liquified butane?
The liquefied butane liquid weighs just about as much as water. |
Does this type of compound have optical isomerism or just geometric isomerism? I have been told that it'll have three isomers, two cis and one trans? Are the two cis isomers optically active? |
In the octahedral comples of type Ma3b2c, how many sterioisomers present? |
Do acetals and hemiacetals give positive 2,4 DNP test?<br>
The reagent for the reaction is described as:
> An aqueous solution of 2,4-dinitrophenyl hydrazine (DNP) is known as Brady's reagent
I recently learnt that acetal don't give positive tollens test whereas hemiacetals did.
Following from the same conclu... |
Do acetals and hemiacetals give 2,4 DNP test? |
From what I understand, to get clear peaks, Pt is analyzed at Pt4f; and Ru at Ru at Ru3d.
However, if i'm not mistaken, charge correction is needed.
But Ru3d(280/284) overlaps with C1s(284)
> So I cannot use C 1s for charge correction
> Hence, I mix in some Au powder and use Au4f(84) for charge correction
... |
In thermodynamics, we get an equation :
$dU = nC_{V}dT$
$\int{dU}= \int{nC_{V}dT}$
Now since $C_{V}$ is independant of temperature for an ideal gas
$ΔU = nC_{V}ΔT$.
But why? Why is $C_{V}$ independent of temperature for an ideal gas? On the other hand, in case of solids and liquids $C_{V}$ may or may not d... |
Why $C_{V}$ for an ideal gas is independant of temperature while $C_{V}$ for solids and liquids may or may not depend on temperature? |
In thermodynamics, we get an equation :
$dU = nC_{v}\mathrm dT$
$$\int{dU}= \int{nC_v\mathrm dT}$$
Now since $C_{v}$ is independant of temperature for an ideal gas
$$ΔU = nC_vΔT$$
Why is $C_v$ independent of temperature for an ideal gas? On the other hand, in case of solids and liquids, $C_{v}$ may or ma... |
Why is the heat capacity of molecules in a system dependent on the universal gas constant, R?
I get how they would be dependent on temperature, but I don't see why they would be dependent on R. Am I overthinking it, is it just a useful constant? |
In thermodynamics we have an equation for the change in internal energy:
$$\mathrm dU = nC_V\,\mathrm dT\tag{1}$$
$$\int{\mathrm dU} = \int{nC_V\,\mathrm dT}\tag{2}$$
Since $C_V$ is independent of temperature, for an ideal gas
$$ΔU = nC_VΔT\tag{3}$$
Why is $C_V$ independent of temperature for an ideal ga... |
In the octahedral complexes of type MA3B2C, how many sterioisomers are present? |
Does $\ce{MA3B2C}$ type have optical isomerism or just geometric isomerism? I was told that it has three isomers, two *cis* and one *trans*. Are the two *cis* isomers optically active? |
How many stereoisomers are present in octahedral complexes of type MA3B2C? |
In the concluding part of my [previous question][1], wouldn't there be an explosion near the hole in the tube from where the excess hydrogen is coming out instead of a steadily burning flame?
[1]: https://chemistry.stackexchange.com/questions/58272/reduction-of-copper-oxide-by-hydrogen-in-the-lab |
> 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?
First I would look at the arguments and see what is the cause. If it's a user deliberately being disruptive, I would definitely warn them. (Repeated disregard o... |
Please explain what is the mistake I have done. Clearly, there are many reactions which take place at constant temperature and have a definite enthalpy change. But according to the equation $dH=nC_{p}dT$, if temperature $T$ is constant then $dT =0$ and $dH =0$. But this is clearly not true. There are reactions with con... |
Suppose a reaction is occuring at constant temperature. Then $dH=nC_{p}dT = nC_{p} ×0=0$. What mistake have I done? |
>Suppose a reaction is occuring at constant temperature. Then $\mathrm dH=nC_{p}\mathrm dT = nC_{p} × 0=0$.
Please explain what the mistake is that I have done. Clearly, there are many reactions which take place at constant temperature and have a definite enthalpy change. But according to the equation $\mathrm dH=nC... |
> [OP] This gives a net 0 (carboxy) + 1 (amino) + 1 (side chain) = +2 charge.
This is approximately correct. See DavePhD's answer for a more accurate treatment.
> [OP] Why do sites such as [this][1] say that at $\mathrm{pH} = 2$, lysine's charge is only +1, not +2?
The table you cite is for proteins. When lysi... |
So I have heard that fluorophores glow under UV light, so I was wondering what is the minimum amount of UV light needed to make the fluorophores glow and what would be the minimum amount of electricity required to make that much amount of UV light. Also, is there any other type of light that makes fluorophores glow but... |
What is the amount of UV light required to make fluorophores glow and what is the minimum amount of electricity needed to achieve this? |
I am researching to opportunity of heat recuperation in the chemical industry be means of high temperature heat pumps. However, I am having some trouble with finding suitable applications. I would like to find overviews of processes (e.g. drying, distillation, thermoforming...) that clearly indicate the heat demand of ... |
I am researching to opportunity of heat recuperation in the chemical industry be means of high temperature heat pumps. However, I am having some trouble with finding suitable applications. I would like to find overviews of processes (e.g. drying, distillation, thermoforming...) that clearly indicate the heat demand of ... |
I need help with this reaction, I know that in the first step an alpha haloketone is formed, but I can't figure out what reaction is going to happen between the alpha Haloketone and $\ce{H2O/H+}$.
[![enter image description here][1]][1]
I read your answers and this is some information and assumptions that I can ... |
So I have heard that fluorophores glow under UV light, so I was wondering what is the minimum amount of UV light needed to make the fluorophores glow and what would be the minimum amount of electricity required to make that much amount of UV light.
Also, is there any other type of light that makes fluorophores glow ... |
Why does gas not liquify at a temperature above the critical temperature no matter how much pressure is applied on it? |
>My textbook says that critical temperature is the temperature above which a gas cannot be liquified no matter how much pressure we apply on it.
Below the critical temperature, you can compress a gas and a second phase (liquid) will gradually form. In places with gravity, the liquid will collect at the bottom of the... |
Graham’s law of diffusion states the rate of diffusion between two gases is inversely proportional to their molar masses. Now, this is helpful when we are focused on two gases. But that is rarely the case in a beaker or even the atmosphere.
So how do you measure the rates of diffusion of many gases moving at once? Do... |
Why does gas not liquify at a temperature above the critical temperature no matter how much pressure is applied on it? Why? |
I'm studying the properties of a natural polymer HPMC( https://pubchem.ncbi.nlm.nih.gov/compound/Hydroxy-propyl-methyl-cellulose)with the static scattering technique, and I'm trying to interpret the molar mass obtained with a Zimm plot, that is (3.08 $\pm$0.47)$\cdot 10^6$ g/mol. In particular I would like to calculat... |
What is the structure formula of a monomer of HPMC (Hydroxy propyl methyl cellulose)? |
> Why must both the critical temperature and pressure be exceeded to achieve the supercritical phase?
Consider the four paths through the phase diagram.
[![enter image description here][1]][1]
Comparing (A) and (C), we are below the temperature of the critical point in (A), so an increase in pressure will liquif... |
I'm studying the properties of a natural polymer [hydroxypropyl methylcellulose (HPMC)](https://pubchem.ncbi.nlm.nih.gov/compound/Hydroxy-propyl-methyl-cellulose) with the static scattering technique. I'm trying to interpret the molar mass obtained with a Zimm plot, that is $\pu{(3.08\pm 0.47)\times 10^{6} g mol^-1}.$
... |
What is the structural formula of a monomer of hydroxypropyl methylcellulose? |
I'm studying the properties of the polymer [hydroxypropyl methylcellulose (HPMC)](https://pubchem.ncbi.nlm.nih.gov/compound/Hydroxy-propyl-methyl-cellulose) with the static scattering technique. I'm trying to interpret the molar mass obtained with a Zimm plot, that is $\pu{(3.08\pm 0.47)\times 10^{6} g mol^-1}.$
In ... |
> However, my problem is that I'm not getting clear enough peaks. The obvious thing I can think of to do is increase the number of scans or lengthen the dwell time.
>
> But I was wondering if there are other solutions other people usually
> do that I might be missing. I do see some papers that try to
> deconvolute... |
From what I understand, to get clear peaks, $\ce{Pt}$ is analyzed at $\ce{Pt}$ 4f; and $\ce{Ru}$ at $\ce{Pt}$ 3d.
However, if i'm not mistaken, charge correction is needed.
But $\ce{Ru}$ 3d(280/284 eV) overlaps with $\ce{C}$ 1s(284 eV), therefore I cannot use $\ce{C}$ 1s for charge correction. Hence, I mix in som... |
When stainless steel is welded, or just heat treated, it will develop a thicker oxide layer, which in some cases is is rainbow colored, but can become so thick as to appear almost black. From the colors (diffraction effects, I assume), the nicer-looking layers must be on the order of a wavelength of light. Is there any... |
How thick is the colored oxide layer on heat treated stainless steel? |
Take aspirin (acetylsalicylic acid) and hydrolyze it with NaOH. This results in sodium acetylsalicylate and water. I think the sodium is held on with an ionic bond, so it is really salicylate dianions that's the important thing in the solution.
This is then diluted to several different concentrations. Using UV-VIS ... |
Why is 295 nm a good wavelength to check absorbance when testing for aspirin? |
> However, my problem is that I'm not getting clear enough peaks. The obvious thing I can think of to do is increase the number of scans or lengthen the dwell time.
>
> But I was wondering if there are other solutions other people usually
> do that I might be missing. I do see some papers that try to
> deconvolute... |
Maybe this isn't the answer you are looking for, but $\ce{^13C}$ NMR shifts are often not amenable towards analysis via electron-withdrawing / electron-donating effects—in my experience this is especially so for aromatic rings. Any such analysis is quite unreliable and can lead to wrong conclusions if you try to use it... |
I think this was basically an educational experiment. Your analytical method assumes that the hydrolysis was complete (*this is the key requirement of a successful calibration curve*). Your experiment did not include a test to assess the completion of hydrolysis. Acetylsalicylic acid begins to hydrolyze in alkaline sol... |
am a student of tropical agriculture, am taking the class of agronomic chemistry and plant nutrition, i want to be able to make use of silicate source i have at home, zeolite, wood ashes, diatomaceous earth, silica sand that i sud for other projects, i have theses three hydroxide calcium, potassium and sodium, can i us... |
Is the name of the compound 3-(ethenyl)-5-(prop-1-enyl)-2-(prop-1-ynyl)-4-(prop-2-enyl)cyclopent-2-en-ol? The problem I am facing is that how do I arrange 5-(prop-1-enyl), 2-(prop-1-enyl) and 4-(prop-2-enyl)? In which order do I write these in the IUPAC name?
, when taken after an initial dose of 800mg for 4 days at 600 mg/day, it was not found to prevent COVID-19 in high-risk exposure settings. Thus, it didn't stop people from getting SARS-CoV-2 infection followed by onset of symptoms/severity.
... |
HCQ does show [antiviral properties in vitro][1], but, in vivo (in humans), when taken after an initial dose of 800mg for 4 days at 600 mg/day, it was not found to prevent COVID-19 in high-risk exposure settings. Thus, it didn't stop people from getting SARS-CoV-2 infection followed by onset of symptoms/severity.
... |
Why does FeF6 not exist? There are hexavalent iron compounds so that is not the problem; there is the Fe(CN)6 ion so there doesn't seem to be a steric problem... |
Existence of iron hexafluoride? |
I am a student of tropical agriculture. I am taking the class of agronomic chemistry and plant nutrition. I want to make use of silicate source I have at home for e.g. zeolite, wood ashes, diatomaceous earth, silica sand. I have hydroxide of calcium, potassium and sodium. Can I use any of these to make silicate for use... |
How to make silicic acid, potassium silicate or calcium silicate? |
Is the name of the following compound **3-(ethenyl)-5-(prop-1-enyl)-2-(prop-1-ynyl)-4-(prop-2-enyl)cyclopent-2-en-ol**?
[![enter image description here][1]][1]
The problem I am facing is that how do I arrange **5-(prop-1-enyl)**, **2-(prop-1-enyl)** and **4-(prop-2-enyl)**. In which order do I write these in the ... |
Why does $\ce{FeF6}$ not exist? There are hexavalent iron compounds, so that is not the problem. There is the $\ce{[Fe(CN)6]^3-}$ ion, so there doesn't seem to be a steric problem. |
Does iron(VI) fluoride exist? |
I was reading about Interhalogens in JD Lee and in the book it is stated that (without any reasoning) the reactivity order for few of the interhalogens is :-<br/>
$\ce{ClF_3 > BrF_5 > IF_7 > ClF > BrF_3 > IF_5 > BrF > IF_3 > IF}$ <br/>
1. $\ce{ClF_3 > BrF_3 > IF_3}$ <br/>
The above is the order for the interha... |
I have been asked to find the total number of dichlorination products (including stereoisomers) for the following reaction:
[![enter image description here][1]][1]
I have figured out nine possible structures out of which two are optically active.
Should I count the additional six isomers (three for each of the... |
Does optical isomerism fall under the category of stereoisomerism? |
Can you please give me the proof of the following equation?
$T_{i}= \frac{2a}{Rb}$
where $T_{i}$ is inversion temperature. And why is it twice of that of Boyle's temperature? |
Why is inversion temperature equal to twice of Boyle's temperature? |
Referring to ncert, Textbook for class XI Chemistry part I, pg no. 117 (At the top) Online downloadable one shows it to be pg no. 113.
[![enter image description here][1]][1].<br>
Here the text puts forward three structures of $\ce{ClF_3}$.
My teacher said to me that (b) structure is unstable due to lone pair lone p... |
> 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?
First I would look at the arguments and see what is the cause. If it's a user deliberately being disruptive, I would definitely warn them. (Repeated disregard o... |
Are the two compounds same? Also, which one is considered bleaching powder? Please explain their differences on the basis of their structures also. |
Are $\ce{CaOCl2}$ and $\ce{Ca(OCl)2}$ same or different? |
Are CaOCl2 and Ca(OCl)2 same or different? |
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... |
> 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?
First I would look at the arguments and see what is the cause. If it's a user deliberately being disruptive, I would definitely warn them. (Repeated disregard o... |
Take [aspirin][1] (acetylsalicylic acid) and hydrolyze it with NaOH. This results in sodium acetylsalicylate and water. I think the sodium is held on with an ionic bond, so it is really salicylate dianions that are the important thing in the solution.
This is then diluted to several different concentrations. Using U... |
Referring to ncert, Textbook for class XI Chemistry part I, pg no. 117 (At the top) Online downloadable one shows it to be pg no. 113.
[![enter image description here][1]][1]
Here the text puts forward three structures of $\ce{ClF_3}$.
My teacher said to me that (b) structure is unstable due to lone pair lone pa... |
What qualifies to be considered as a lone pair-lone pair repulsion? |
> 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?
First I would look at the arguments and see what is the cause. If it's a user deliberately being disruptive, I would definitely warn them. (Repeated disregard o... |
I have been asked to determine the nature of the product for the following reaction:
[![enter image description here][1]][1]
And as I recognized this reaction to be a case of *syn-dihydroxylation*, my obvious response was that the product formed will be *meso*.
But, in the solution to the problem, it says it... |
Does syn-dihydroxylation form racemic mixture? |
I have been asked to determine the major product for the reaction:
[![enter image description here][1]][1]
From the reagent given, one can tell that this is an epoxidation reaction. But, as only one mole of the peroxyacid is given, epoxidation can only take place in one of the two bonds.
How do you determine ... |
The test for anions can be done with a platinum wire and a Bunsen flame.
My textbook says that it can also be done by preparing a solution of the given salt in water and ethanol and spraying it onto the Bunsen flame.
How do I prepare this solution in terms of how much water, ethanol and salt ? |
> 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 think the site doesn't work if we can't interact in a civil way, so frequent fights or abusive behavior outweighs useful content. Often these sorts of dispute... |
I was working on an assignment I had a question about conformations of a molecule about a single bond.
Given a random molecule like this with multiple large substituents on one side of the C-C bond (in this case, ${CH_3}$ & ${C_2H_5}$), is the molecule considered to be anti when the largest substituents on either si... |
We were asked in class which have the lower $pK_a$ values: terminal alkynes or non-terminal alkynes. The teacher told that terminal alkynes have the lowest $pK_a$ values without really explaining why.
Please provide some explanation on this: why terminal alkynes have lower $pK_a$ values than non-terminal alkynes? |
We were asked in class which have the lower $\mathrm{p}K_a$ values: terminal alkynes or non-terminal alkynes. The teacher told that terminal alkynes have the lowest $\mathrm{p}K_a$ values without really explaining why.
Please provide some explanation on this: why terminal alkynes have lower $\mathrm{p}K_a$ values t... |
We were asked in class which have the lower $\mathrm{p}K_a$ values: terminal alkynes or non-terminal alkynes. The teacher told that terminal alkynes have the lowest $\mathrm{p}K_a$ values without really explaining why.
Please provide some explanation on this: Why do terminal alkynes have lower $\mathrm{p}K_a$ value... |
Why do terminal alkynes have lower pKa values than non-terminal alkynes? |
I'm reading something at the moment where they state:
>This reagent has enhanced basicity as it benefits from the high kinetic basicity of alkoxides compared to alkyls.
This is in the context of organometallics so we're talking about a negatively charged alkoxide ligand versus a negatively charged alkyl ligand.
... |
I was working on an assignment I had a question about conformations of a molecule about a single bond.
Given a random molecule like this with multiple large substituents on one side of the $\ce{C-C}$ bond (in this case, $\ce{CH3}$ & $\ce{C2H5}$), is the molecule considered to be anti when the largest substituents on... |
> In a solution of Fe$^3+$ the concentration was measured to be:
$$\begin{array}{c|c|c|}
& \text{t/min} & \text{[Fe3+]/µM} \\ \hline
\ & 10\ & 238\\ \hline
\ & 20 & 227\\ \hline
\ & 40\ & 206\\ \hline
\ & 60\ &187 \\ \hline
\ & 80\ &169\\ \hline
\ & 100\ &154 \\ \hline
\end{array}$$
>The decrease in Fe$^3+$... |
Is there any theoretical/hypothetical way through which a gas can be liquified above critical temperature? For example applying inifinjte amount of pressure to the system? |
$\ce{ZnS}$ is a boring white powder and it doesnt glow in the dark, but if its doped with silver it starts to show some phosphorescent properties.How does silver force zinc sulfide to do that? |
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