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KBr reacts with concentrated H3PO4 to give HBr and (KH2PO4 or K3PO4) (not sure which one, if someone knows it, please tell).
Why isn't bromine gas liberated? |
Why doesn't KBr + concentrated H3PO4 not give Br2? |
if there is a ketone and ester functional group in one same compound and I want to protonate with HCl, which one will protonate first? is it the carbonyl group in the ketone or the carbonyl group in the ester? and why? is it related to the PkA of the functional group? |
If there is a ketone and ester functional group in one same compound and I want to protonate with HCl, which one will protonate first? Is it the carbonyl group in the ketone or the carbonyl group in the ester? And why? Is it related to the $pK_a$ of the functional group? |
$\ce{KBr}$ reacts with concentrated $\ce{H3PO4}$ to give $\ce{HBr}$ and ($\ce{KH2PO4}$ or $\ce{K3PO4}$) (not sure which one, if someone knows it, please tell).
Why isn't bromine gas liberated? |
Which of the following statements is true regarding an ionic bond in FeS? |
> B) Iron and sulfur ions bond by electrostatic attraction. <br/>
This is the right answer. I see a hard time maneuvering around it.
> D) Breaking an ionic bond between $\ce{Fe^2+}$ and $\ce{S^2-}$ releases energy.
Around the basic definition of forces and bonds, there are usually two big beliefs. One is a bi... |
> B) Iron and sulfur ions bond by electrostatic attraction. <br/>
This is the right answer. I see a hard time maneuvering around it.
> D) Breaking an ionic bond between $\ce{Fe^2+}$ and $\ce{S^2-}$ releases energy.
Around the basic definition of forces and bonds, there are usually two big beliefs. One is a bi... |
Does salt vaporise? If I boil a salty water and leave it there until half of the water vaporises, will it be twice as salty as in the beginning? Or exactly the same? Or somewhere in between? |
Does salt vaporise? |
I know that the definition of molecularity of a reaction is number of species reacting in an elementary step. But considering the theory of microscopic reversibility for elementary reactions, each reaction can be assumed to be reversible. In that case, if A <--> B + C then what is the molecularity of the reaction? Is i... |
What is the molecularity of a reversible reaction? |
If there is a ketone and ester functional group in one same compound and I want to protonate with $\ce{HCl}$, which one will protonate first? Is it the carbonyl group in the ketone or the carbonyl group in the ester? And why? Is it related to the $\mathrm{p}K_\mathrm{a}$ of the functional group? |
I know that the definition of molecularity of a reaction is number of species reacting in an elementary step. But considering the theory of microscopic reversibility for elementary reactions, each reaction can be assumed to be reversible. In that case, if $$\ce{A <-> B + C}$$ then what is the molecularity of the reacti... |
Are glycans, such as glucose, considered alicyclic compounds? |
Activated complex theory, tells us that due to the collision between the molecules of the reactants, they form a transition specie before the product is formed, which is called active complex. On the other hand we have consecutive reactions on which is also formed a intermediate product before forming the actual produc... |
If I am given a compound which belongs to, say the cubic $\text{Ia}\bar 3\text{d}$ space group, is there a known way to calculate the lattice parameter of the compound? In general, can lattice parameters be calculate from knowing what space group the compound belongs to? |
When using Pymol or Coot molecular visualization software to solve x-ray crystallography structures, how can I mutate a cytosine to a 5-methylcytosine? |
I just noticed that picric acid is more acidic than carbonic acid(h2co3, not phenol). I have no idea why? Is there some rule I'm missing or is this one of those exceptions that I just have to remember? |
I'm having a bit of trouble grasping sugar stereochemistry.
Using glucose as an example, if you cyclize D and L glucose, is the stereochemistry at every carbon just inverted from the other form?
Like for example, on carbon 2 for D glucose, the hydroxyl is down. On carbon 2 for L glucose, the hydroxyl would be up... |
In the Haworth projections of D and L glucose, is the stereochemistry at every carbon except the anomeric carbon just inverted? |
I'm having a bit of trouble grasping sugar stereochemistry.
Using glucose as an example, if you cyclize D and L glucose, is the stereochemistry at every carbon just inverted from the other form?
Like for example, on carbon 2 for D glucose, the hydroxyl is down. On carbon 2 for L glucose, the hydroxyl would be up... |
I just noticed that picric acid is more acidic than carbonic acid ($\ce{H2CO3}$, not phenol). I have no idea why? Is there some rule I'm missing or is this one of those exceptions that I just have to remember? |
I was reading the R.A. Millikam's oil drop experiment and the following part confused me:-
"By measuring the rate of fall, Millikam was able to measure the fall of the oil droplets (which were dropped through a tiny hole in the upper electrical condenser)".
Now In Newtonian physics, the rate of fall(or velocity) of a... |
How did Millikam measure the mass of these oil droplets? |
I was reading the R.A. Millikan's oil drop experiment and the following part confused me:-
"By measuring the rate of fall, Millikan was able to measure the fall of the oil droplets (which were dropped through a tiny hole in the upper electrical condenser)".
Now In Newtonian physics, the rate of fall(or velocity) of a... |
How did Millikan measure the mass of these oil droplets? |
I'm really confused about this . If we consider $\ce{Ca3(PO4)2}$, it can be seen it undergoes an equilibrium.But why it's an equilibrium?
This is the equilibrium it undergoes ![enter image description here][1]
By the way I'm having a doubt of why some are using backward arrow for a dissociation of a partic... |
Do all the precipitates undergo an equilibrium with it's respective ions, why can't they dissociate fully? |
Both these processes are used in concentration of bauxite.
They use different reagents.
Which is more commonly used ([wikipedia says Bayer's][1]) and why?
When is one preferred over the other?
Which is more efficient and why?
[1]: http://en.m.wikipedia.org/wiki/Bayer_process#History_of... |
When is Serpeck's process preferred over Bayer's process? |
Electeothermal atomizer ( graphite furnance ) and flame atomizer, are the instruments which help us to convert the analyte into the gas state and they both achieve that. My question is, what's the difference in their way of workig ? I know the flame has its nebulisator which converts the liquid analyte into mist aeroso... |
Background: Glycerine, when heated with a metal coil, decomposes below its boiling point to acrolein, which in turn appears to decompose to formaldehyde and acetaldehyde. ([see previous post][1])
Question: Is there a chemical that could be added, or a process that could be applied, that would lessen the decompositio... |
this may seem silly, but doesn't it seem weird for a compound that's stable(in this context, the tertiary carbocation) to be the most reactive? i mean, wouldn't it be the least, given that it's already stable and wouldn't wanna leave that stable configuration... on the same lines, the methyl carbocation sounds like the... |
Why are tertiary carbocations the most reactive, if they're already stable? |
Electeothermal atomizer ( graphite furnance ) and flame atomizer, are the instruments which help us to convert the analyte into the gas state and they both achieve that. My question is, what's the difference in their way of workig ? I know the flame has its nebulisator which converts the liquid analyte into mist aeroso... |
This may seem silly, but doesn't it seem weird for a compound that's stable (in this context, the tertiary carbocation) to be the most reactive?
I mean, wouldn't it be the least, given that it's already stable and wouldn't want to leave that stable configuration. On the same lines, the methyl carbocation sounds lik... |
I was wondering whether the following order is correct:
- In the **first inequality**, why did 9 hyperconjugation dominated resonance effect of benzene ring?
- In the **last inequality** doesn't 2 hyperconjugation of viny... |
I was wondering whether the following order is correct:
- In the **first inequality**, why did 9 hyperconjugations dominated resonance effect of benzene ring?
- In the **last inequality** doesn't the 2 hyperconjugations o... |
Why are multi-quantum coherences unobservable in regular NMR experiments ? |
I'm really confused about this . If we consider $\ce{Ca3(PO4)2}$, it can be seen it undergoes an equilibrium.But why it's an equilibrium?
This is the equilibrium it undergoes $$\ce{Ca3(PO4)2_{(s)}<=> 3Ca^2+_{(aq)} + 2 PO4^3-_{(aq)} }$$
By the way I'm having a doubt of why some are using backward arrow for a... |
Very interesting question. This also popped up in my head once. And this is how I convinced myself.
The confusing term here is stability. Tertiary carbocations are stable by inductive effect and hyper conjugation, and therefore have the tendency to sustain the positive charge on the carbon atom and stay like this fo... |
I'm really confused about this . If we consider $\ce{Ca3(PO4)2}$, it can be seen it undergoes an equilibrium.But why it's an equilibrium?
This is the equilibrium it undergoes $$\ce{Ca3(PO4)2_{(s)}<=> 3Ca^2+_{(aq)} + 2 PO4^3-_{(aq)} }$$
By the way I'm having a doubt of why some are using backward arrow for a... |
I wanted to ask something more in reference to this question http://chemistry.stackexchange.com/questions/7683/ortho-effect-in-substituted-aromatic-acids-and-bases
![2 methoxy aniline][1]
![enter image description here][2]
Suppose instead of toluidine,**2-Methoxy aniline** and **3-Methoxy aniline** are pres... |
I wanted to ask something more in reference to this question http://chemistry.stackexchange.com/questions/7683/ortho-effect-in-substituted-aromatic-acids-and-bases
![2 methoxy aniline][1]
![enter image description here][2]
Suppose instead of toluidine,**2-Methoxy aniline** and **3-Methoxy aniline** are pres... |
Why are multi-quantum coherences unobservable in regular NMR experiments ? This is relevent to the DQ-filter experiment which exploits this property.
|
I know that the definition of molecularity of a reaction is number of species reacting in an elementary step. But considering the theory of microscopic reversibility for elementary reactions, each reaction can be assumed to be reversible. In that case, if $$\ce{A <=> B + C}$$ then what is the molecularity of the reacti... |
From [this source](http://www.2classnotes.com/digital_notes.asp?p=Extraction_of_Aluminium)
>Baeyer's process: This method is mainly applied when ferric oxide is present as chief impurity.
>Serpeck's process: This process is used when silica is present in considerable amount of bauxide ore.
I couldn't find any ... |
What program could I use to create a protein from nothing? |
![4-Nitrobenzoic acid][1]
![4-Methoxybenzoic acid][2]
[1]: https://i.stack.imgur.com/UUHqS.png
[2]: https://i.stack.imgur.com/dWTVG.png
Comparing the acidic strength, the nitro-substituted group is definitely more acidic. This can be reasoned by fact that a higher delta positive charge which develops on the... |
Alanine is heavier with a ($\ce{-CH3}$) than glycine which has an ($\ce{-H}$). What makes them have different $\mathrm{p}K_\text{a}(\ce{-NH3+})$ $(\mathrm{p}K_\text{a}: \text{Ala}=9.69, \text{Gly}=9.60)$ but similar $\mathrm{p}K_\text{a}(\ce{-COOH})$ $(\mathrm{p}K_\text{a}=2.34)$ when the rest of the amino acid is simi... |
I wanted to ask something more in reference to this question http://chemistry.stackexchange.com/questions/7683/ortho-effect-in-substituted-aromatic-acids-and-bases
![2 methoxy aniline][1]
![enter image description here][2]
Suppose instead of toluidine, **2-methoxy aniline** and **3-methoxy aniline** are pre... |
How do we number the carbon atoms in symmetrical molecules while giving R and S notation. For instance, in 2,3-Dibromobutane, there is an ambiguity over which is carbon C2 and carbon C3. Will we call it (2R,3S) or (2S,3R)?
![enter image description here][1]
[1]: https://i.stack.imgur.com/w21zN.png |
What program could I use to create a protein model from scratch? |
Why cooling an exothermic solution it increases it's solubility? |
A scientist has a sample of uranium-238 (U-238) that is decaying to thorium-234 (Th-234). During the transmutation, a gamma ray is emitted from the nucleus. The thorium-234 daughter particle does not decay quickly enough to be detected. What kind of storage container should he store the sample in to reduce radiation ex... |
Why do ketenes participate in [2+2] cycloadditions with their C=C bond and not the C=O bond? Can the reactivity be reversed somehow? |
Why do ketenes participate in [2+2] cycloadditions with their $\ce{C=C}$ bond and not the $\ce{C=O}$ bond? Can the reactivity be reversed somehow? |
This may not be the best place to look, but if anyone could answer my question or help point me in the right direction I would greatly appreciate it.
A little context: I make craft chili oils for friends and family. I use a two-step process. First, I infuse the oil for flavor. Second, I add the dried chili flakes in... |
A little context: I make craft chili oils for friends and family. I use a two-step process. First, I infuse the oil for flavor. Second, I add the dried chili flakes into flavored oil the in two batches. I have used canola and grapeseed oil.
Questions:
-Is there an ideal temperature to best extract flavors (for ex, ... |
A little context: I make craft chili oils for friends and family. I use a two-step process. First, I infuse the oil for flavor. Second, I add the dried chili flakes into the flavored oil. I have used canola and grapeseed oil.
Questions:
-Is there an ideal temperature to best extract flavors (for ex, from cumin seed... |
I put a copper wire through a hole in the cap of a water bottle, filled the water bottle ~ half way full with vinegar, and left it over night. The part of the wire inside the bottle that wasn't in vinegar turn black. Really black. Why is this?!
UPDATE: I wiped the black stuff off on paper, and it now looks green ... |
On Wikipedia, it says that "NiCl<sub>2</sub>·6H<sub>2</sub>O consists of separated trans-[NiCl2(H2O)4] molecules linked more weakly to adjacent water molecules. Only four of the six water molecules in the formula are bound to the nickel, and the remaining two are water of crystallisation.[4] Cobalt(II) chloride hexahyd... |
How many electrons in the d orbitals of NiCl2·6H2O? |
On Wikipedia, it says that
> $\ce{NiCl2·6H2O}$ consists of separated trans-$\ce{[NiCl2(H2O)4]}$ molecules
> linked more weakly to adjacent water molecules. Only four of the six
> water molecules in the formula are bound to the nickel, and the
> remaining two are water of crystallisation.[4] Cobalt(II) chloride
... |
Can I get an accurate temperature reading from a flask with a built-in thermometer well? |
What is the justification for Huckel's Rule? |
In Wikipedia's article for [Michaelis-Menten kinetics](http://en.wikipedia.org/wiki/Michaelis%E2%80%93Menten_kinetics#Quasi-steady-state_approximation), it titles the "[ES] = constant" section the "Quasi-steady-state approximation". Lehninger's *Principles of Biochemistry*, 4th Ed. pp. 203ff call this "steady state kin... |
How is the "quasi-steady-state" assumption of Michaelis-Menten kinetics different from the steady state assumption of ordinary kinetics? |
> Is Wikipedia's use of "quasi" in the title for the enzyme kinetics reflective of [...] the further assumption that $[S]$ is constant[...]?
No I don't think the "quasi-steady state" hypothesis is related to $[S]$ varies with time.
>[W]hy add a further descriptor that denotes uncertainty or inaccuracy when we a... |
$$H=U+pV$$
Above is the formula for enthalpy or the sum of the internal energy and pressure volume product.
$-p\Delta V$ is work done by or on the system. But $pV$, yet very similar to work, I think, calculates the whole “cylinder”. Instead of just calculating the height difference of the cylinder before and afte... |
I would like to obtain the 3D charge density of a water molecule for plotting purposes (i.e. not necessarily super-accurate). I know this is a tough problem, but I'd like to give it a try. Since I'm currently using python, I've identified PyQuante and PySCF, and gather that I should learn how to run DFT calculations, b... |
First of all, any 'tin' can you are likely to find is actually made of steel. Tin is too expensive. Also, tin does not 'rust', although it oxidizes. Your rust is iron oxide. Galvanized steel is steel with a thin zinc coating, likely hot-dip galvanization. What you describe (crystalline surface or spangles sort of appea... |
What is the specific gravity of H2O2 bleached viscose? In literature I can find that this is 1.52 gm/cm3, but for bleached viscose is it not findable. Can I presume H2O2 treated viscose has the same density? |
What is the specific gravity of $\ce{H2O2}$ bleached viscose? In literature, I can find that this is 1.52 gm/cm<sup>3</sup>, but for bleached viscose is it not findable. Can I presume $\ce{H2O2}$ treated viscose has the same density? |
I would like to obtain the 3D charge density of a water molecule for plotting purposes (i.e. not necessarily super-accurate). I know this is a tough problem, but I'd like to give it a try. Since I'm currently using python, I've identified PyQuante and PySCF, and gather that I should learn how to run DFT calculations, b... |
I’m really confused about this. If we consider $\ce{Ca3(PO4)2}$, it can be seen it undergoes an equilibrium. But why it’s an equilibrium?
This is the equilibrium it undergoes $$\ce{Ca3(PO4)2_{(s)}<=> 3Ca^2+_{(aq)} + 2 PO4_{(aq)}^3-}$$
By the way I’m having a doubt of why some are using backward arrow for a dissoc... |
Do all the precipitates undergo an equilibrium with its respective ions, why can't they dissociate fully? |
Why is the stability of (b) greater than that of (a)?
![enter image description here][1]
[1]: https://i.stack.imgur.com/7Rjp8.jpg
Here are my thoughts:
Since (a) contains a Trans C=C portion instead of a Cis C=C, it should experience less steric repulsion and hence be stabler.
The answer in my textbook (Solomons... |
The first question to always ask when you are trying to build an MO diagram is what point group does my molecule fall into? In this case, the CH2 molecule has C2V symmetry (like the water example shown above). Each of the atomic orbitals (AO's) on carbon (left) and the combination of 1s orbitals on the hydrogen at... |
I need to know if a combination of bleach and the chemicals below will create poisonous gas. Will it create chloramine, and will there be any visible gas?
1) Sodium laureth sulfate
2) Sodium citrate
3) C12-14 Pareth-3 |
Will bleach combined with any of these chemicals create poisonous gas? |
I found a [thread][1] which discussed this which totally confused me. (refer to the part of the link which talks about sp2/sp3)
Can someone help me out?
Thanks.
[1]: http://forums.studentdoctor.net/threads/why-is-aniline-aromatic.623668/ |
Is nitrogen of aniline sp2 or sp3 hybridized? |
The first question to always ask when you are trying to build an MO diagram is what point group does my molecule fall into? In this case, the CH2 molecule has C2V symmetry (like the water example shown above). Each of the atomic orbitals (AO's) on carbon (left) and the combination of 1s orbitals on the hydrogen at... |
I know this is easy and I know I should divide g/L by the molar mass of the substance, but I don't seem to find the specific answer on google. So just to be sure :
If i have 10^-5 g/L Cu 2+ solution,
Do i have 1.57 x 10^-7 mol/L ? |
> I need to know if a combination of bleach and the chemicals below will create poisonous gas.
> Sodium laureth sulfate
Sodium laureth sulfate is $\cf{CH3(CH2)11(OCH2CH2)_{\bf{3}}OSO3Na}$, where the boldface 3 is an approximation and can actually vary between 1 and 5 or so. The key point is it contains no nitrog... |
I know this is easy and I know I should divide g/L by the molar mass of the substance, but I don't seem to find the specific answer on google. So just to be sure :
If i have 10^-5 g/L Cu 2+ solution,
Do i have 1.57 x 10^-7 mol/L ?
I think I'm missing something
|
I know this is easy and I know I should divide g/L by the molar mass of the substance, but I don't seem to find the specific answer on google. So just to be sure :
If i have $10^{-5}$ g/L $\cf{Cu^{+2}}$ solution, do I have $1.57 \times 10^{-7}$ mol/L ?
I think I'm missing something.
|
I have been trying to get a relationship formula to determine the viscosity of Linseed oil. I have Absolute viscosity of the oil at 33.1 Cp (Source: http://www.engineeringtoolbox.com/absolute-viscosity-liquids-d_1259.html).
The problem is the system where I am using the fluid has a varying temperature, and I want t... |
Relation between Temperature and viscosity of Linseed Oil? |
Why is the stability of (b) greater than that of (a)?
![enter image description here][1]
[1]: https://i.stack.imgur.com/7Rjp8.jpg
Here are my thoughts:
Since (a) contains a Trans C=C portion instead of a Cis C=C, it should experience less steric repulsion and hence be stabler.
The answer in my textbook... |
Why is the stability of (b) greater than that of (a)?
![enter image description here][1]
[1]: https://i.stack.imgur.com/7Rjp8.jpg
Here are my thoughts:
Since (a) contains a *trans* double bond instead of a *cis* double bond, it should experience less steric repulsion and hence be more stable.
The answe... |
I found a [thread][1] which discussed this which totally confused me. (refer to the part of the link which talks about sp2/sp3)
http://chemistry.stackexchange.com/questions/4390/resonance-structure-and-hybridisation this question is helpful but doesn't have aniline specifically. I understand that if lone pair is i... |
I found a [thread][1] which discussed this which totally confused me. (refer to the part of the link which talks about $\ce{sp^2/sp^3}$)
http://chemistry.stackexchange.com/questions/4390/resonance-structure-and-hybridisation this question is helpful but doesn't have aniline specifically. I understand that if lone ... |
I was wondering why a hydrogen attached to a nitrogen or oxygen is not able to couple with p+ on adjacent carbon atoms and hence why it always appeats as a singlet in HNMR spectroscopy? |
I need some ethanol pure and strong enough for technical purposes (fuel, solvent, cleaning agent, dissolving rosin for soldering flux, etc.). Food quality is not required though, denaturated one is fine too. Distilling cheap vodka is possible, but even cheap vodka is expensive because of high tax on food ethanol; also ... |
How can I purify ethanol from formic / boric / salicylic acid? |
It depends on the condition of your experiment if a coupling of a proton of an amino or hydroxyl group with a proton attached to the $\alpha{}$-carbon is observable, or not. As pointed out by the indicator set by @Mithoron, intermolecular exchange processes need to be taken into account.
- If your alcohol (or amin... |
I need some ethanol pure and strong enough for technical purposes (fuel, solvent, cleaning agent, dissolving rosin for soldering flux, etc.). Food quality is not required though, denaturated one is fine too. Distilling cheap vodka is possible, but even cheap vodka is expensive because of high tax on food ethanol; also ... |
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