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I've always wondered by the N-glycosidic bond connecting adenine or guanine purine bases to their sugars was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers that makes ... |
Why does depurination happan at a higher pH (or under less harsh conditions) than depyrimidation? |
If you have CH3`CH2`CH3BR
Then the CH2 (in bold) would have a peak splitting of 12 because (n+1)(m+1)
where n for the CH3 is (3+1=4) and m for CH2 is (2+1=3) so its 4X3=12
source:
![enter image description here][1]
But in the other textbook it says:
CH3`CH2`CH2COOH
The CH2 (in bold) has a peak splittin... |
I've always wondered by the N-glycosidic bond connecting adenine or guanine purine bases to their sugars was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers that makes ... |
If you have CH3`CH2`CH3BR
Then the CH2 (in bold) would have a peak splitting of 12 because (n+1)(m+1)
where n for the CH3 is (3+1=4) and m for CH2 is (2+1=3) so its 4X3=12
source:
![enter image description here][1]
But in the other textbook it says:
CH3`CH2`CH2COOH
The CH2 (in bold) has a peak splittin... |
Is there a database or a website with a list of oil : water partition coefficients of substances ?
I actually want the oil:water partition coefficients of :
cholesterol, starch , methyl citrate , citric acid , iso- citrate , methyl urea , carotene
|
I've always wondered by the N-glycosidic bond connecting adenine or guanine purine bases to their sugars was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers that makes ... |
My question is: Is hydrogen-rich water true? I am aware of the alkaline water. I have read several articles in the Internet regarding this kind of water but I cannot seem to be convinced. Wikipedia isn't even talking about it.
I am puzzled with how can a water be enriched with hydrogen. It's definitely $\ce{H2O}$ an... |
I've always wondered by the N-glycosidic bond connecting adenine or guanine purine bases to their sugars was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers that makes ... |
If you have CH3`CH2`CH2BR
Then the CH2 (in bold) would have a peak splitting of 12 because (n+1)(m+1)
where n for the CH3 is (3+1=4) and m for CH2 is (2+1=3) so its 4X3=12
source:
![enter image description here][1]
But in the other textbook it says:
CH3`CH2`CH2COOH
The CH2 (in bold) has a peak splittin... |
If you have CH3`CH2`CH2BR
Then the CH2 (in bold) would have a peak splitting of 12 because (n+1)(m+1)
where n for the CH3 is (3+1=4) and m for CH2 is (2+1=3) so its 4X3=12
source:
![enter image description here][1]
> In the general case, a signal will be split into (n + 1) x (m + 1)
> peaks for an H atom ... |
I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers ... |
Why does depurination happen at a higher pH (or under less harsh conditions) than depyrimidation? |
If you have $\ce{CH3-\color{\red}{CH2}-CH2Br}$
Then the $\ce{CH2}$ (in red) would have a peak splitting of $12$ because $(n+1)(m+1)$
where $n$ for the $\ce{CH3}$ is $(3+1=4)$ and m for $\ce{CH2}$ is $(2+1=3)$ so its $4\times3=12$
source:
![enter image description here][1]
> In the general case, a signal wi... |
How can I make $\ce{Cu2O}$ from copper?
I am seeing if electrolysis is a good route (in the context of kitchen style chemistry) to cuprous oxide, instead of the traditional heating copper and removing the cupric oxide, etc.
With Epsom salt electrolyte, it is very easy to make copper II hydroxide (cloudy ammonia s... |
What are the mechanisms for the reduction of organic compounds employing red phosphorus and iodine? |
I have been going through reduction of aldehydes using $\ce{LiAlH4}$ and $\ce{NaBH4}$. If there is a double bond in the compound $\ce{LiAlH4}$ doesn't affect it. In 40% of the reduced product, using $\ce{NaBH4}$, the double bond too will be reduced. Why is it so?
I know that $\ce{LiALH4}$ produces hydrogen in a cont... |
Why does NaBH4 affect double bonds while LiALH4 does not? |
I faced this reaction which can be balanced in $2$ distinct ways which are **not** multiples of each other.
$$\ce{6XeF4}+\ce{12H2O} \to \ce{2XeO3}+\ce{24HF}+\ce{4Xe}+\ce{3O2}$$
$$\ce{4XeF4}+\ce{8H2O} \to \ce{2XeO3}+\ce{16HF}+\ce{2Xe}+\ce{O2}$$
The first reaction is as it is given in the books and the second ... |
I was wondering why specific number of water molecules are attached to salts like $\ce{CuSO4.5H2O}$? Searching gave me a satisfying picture :
![enter image description here][1]
I think $\ce{FeSO4.7H2O}$
should have a similar structure with $6$ water molecules in coordination sphere. But what about $\ce{MgSO4.7... |
Why $\ce{MgSO4.\color\red{7}H2O}$? |
The question is:
![Hydrolysis][1]
[1]: https://i.stack.imgur.com/cZ4sA.jpg
I know that initially a cyanohydrin will be formed. On reaction with $\ce{H2SO4}$, the cyanohydrin will give a carboxylic acid/an amide. Since the medium is highly concentrated acid medium(95% $\ce {H2SO4}$), the quantity of water i... |
The question is(See image):
![Hydrolysis][1]
[1]: https://i.stack.imgur.com/cZ4sA.jpg
I know that initially a cyanohydrin will be formed. On reaction with $\ce{H2SO4}$, the cyanohydrin will give a carboxylic acid/an amide. Since the medium is highly concentrated acid medium(95% $\ce {H2SO4}$), the quantity... |
I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers ... |
The question is(See image):
![Hydrolysis][1]
[1]: https://i.stack.imgur.com/cZ4sA.jpg
I know that initially a cyanohydrin will be formed. On reaction with $\ce{H2SO4}$, the cyanohydrin will give a carboxylic acid/an amide. Since the medium is highly concentrated acid medium(95% $\ce {H2SO4}$), the quantity... |
I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers ... |
The answer lies mostly with size. Think of a BB gun pellet and a basketball. How many basketballs can you stick to the sides of a BB gun pellet? 2, maximum. That's why some metal cations are hydrated with fewer waters than others; these metal cations tend to be the smaller ones.
Also, it is not $\ce{FeSO4}$ that is... |
The answer lies mostly with size. Think of a BB gun pellet and a basketball. How many basketballs can you stick to the sides of a BB gun pellet? 2, maximum. That's why some metal cations are hydrated with fewer waters than others; these metal cations tend to be the smaller ones.
Also, it is not $\ce{FeSO4}$ that is... |
*I have given two answers: one regarding the hydration of metal cations _in solution_ and one regarding salts of metal cations and their hydration extents.*
**When in solution, the answer lies with size.** Think of a BB gun pellet and a basketball. How many basketballs can you stick to the sides of a BB gun pellet?... |
*I have given two answers: one regarding the hydration of metal cations in solution and one regarding salts of metal cations and their hydration extents.*
**When in solution, the answer lies with size.** Think of a BB gun pellet and a basketball. How many basketballs can you stick to the sides of a BB gun pellet? 2... |
For Magnesium Sulphate heptahydrate, again 6 waters coordinate the Mg2+.
The crystal structure is plublished as [Refinement of the Crystal Structure of Magnesium Sulphate Heptahydrate (Epsomite) by Neutron Diffraction][1]
In the case of (Di)Sodium Carbonate Decahydrate, again 6 waters coordinate each sodium, but... |
What's the difference between PBE and B3LYP methods? |
For Magnesium Sulphate heptahydrate, again 6 waters coordinate the Mg2+. The 7th water is hydrogen bonded, but not coordinated to the Mg2+.
The crystal structure is plublished as [Refinement of the Crystal Structure of Magnesium Sulphate Heptahydrate (Epsomite) by Neutron Diffraction][1].
Magnesium Sulphate he... |
The question is(See image):
![Hydrolysis][1]
[1]: https://i.stack.imgur.com/cZ4sA.jpg
I know that initially a cyanohydrin will be formed. On reaction with $\ce{H2SO4}$, the cyanohydrin will give a carboxylic acid/an amide.
**Here's my doubt:**
Since the medium is highly concentrated acid medium(95% ... |
I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers ... |
I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers ... |
I think there's a basic idea I'm missing about 3 Dimensional representation of molecules. I think it may be about converting to Fischer representation. Consider the following two products of bromination of an alkene, the first one being for cis-form and the 2nd one for trans-form.
![3d representation][1]
[1]:... |
What is there in this 3D representation of organic molecules I fail to grasp? |
I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers ... |
I've always wondered why the N-glycosidic bond, which connects the adenine or guanine purine bases to their sugars, was the easiest to cleave via acid hydrolysis, or why purines have the lowest ionization potentials? What is it about the rings / resonance / etc. of purine vs. pyrimidine bases in nucleic acid polymers ... |
Consider nitrous oxide, which has a real bond order of 2.5, contrary to what this UC Davis rendering might imply:
![enter image description here][1]
[1]: https://i.stack.imgur.com/KjHIC.jpg
What's the best way to visualize a molecule with a fractional bond order? What exactly is "half a bond"? The electron... |
Fractional Bond Order - How to Visualize? |
Consider nitric oxide, which has a real bond order of 2.5, contrary to what this UC Davis rendering might imply:
![enter image description here][1]
[1]: https://i.stack.imgur.com/KjHIC.jpg
What's the best way to visualize a molecule with a fractional bond order? What exactly is "half a bond"? The electron ... |
A rule of thumb in chemistry is that a reaction doubles in rate for every 10C increase in temperature. Considering the impact of a 10C increase in global temperature, would the same rule apply to kinetic weather processes - for example, would the average wind speed around the world double? |
I was watching [Periodic Video's chlorine video][1], which discusses Chlorine's ferocity in stripping electrons whenever possible, and the professors mentioned its consequent use in WWII as a chemical agent. This got me thinking, if I were in that situation (say Syria if they decided to go old-school or a chemical leak... |
Maybe some examples will help. In the picture below, I've drawn some resonance structures for butadiene and acrolein. What do they tell us? They suggest that the central "single" bond should have some double bond character, it's more than a single bond, but less than a double bond. By the same token, the "double"
... |
Would these be valid conformations of butane? I tried matching these up with the group but my drawings all seem rotated verses the book.
I'm fairly sure my anti conformer is correct, along with my gauche conformer. I'm not too sure about the two eclipsed conformers; from what I understand, there are two eclipsed co... |
Would these be valid conformations of butane? I tried matching these up with the group but my drawings all seem rotated verses the book.
I'm fairly sure my anti conformer is correct, along with my gauche conformer. I'm not too sure about the two eclipsed conformers; from what I understand, there are two eclipsed co... |
We were told to rinse the buret with the base so that the concentration won't be messed up
but when it comes to the flask that is going to hold the acid, there is not need to rinse because it would not affect the result if it has water in it.
Why is that? Wouldn't the acid be diluted a little bit and that throws of... |
How come water would not affect the results of a titration? |
Would these be valid conformations of butane? I tried matching these up with the group but my drawings all seem rotated verses the book.
I'm fairly sure my anti conformer is correct, along with my gauche conformer. I'm not too sure about the two eclipsed conformers; from what I understand, there are two eclipsed co... |
The volume and concentration of base equals the number of moles of base. This is use to determine the number of moles of acid in the flask. Since you are interested in the number of moles of acid in the flask, why would adding water (which doesn't have any acid) change the number of moles of acid? |
My teacher insists that we can push electrons either from a bond to an atom's valence, or vice versa. Bond to lone pair; lone pair to bond, he insists.
However, what about bond to bond?
Is there a pedagogical reason he might be avoiding bond-to-bond movement? This is a legal move.
Or does he simply not see b... |
We are doing an experiment and would like to be able to identify zinc/aluminium/ magnesium . Would a copper sulphate solution work ? I hear that it turns black on contact with zinc, stays clear on contact with aluminium and fizzes on contact with magnesium.. Many thanks
James |
A rule of thumb in chemistry is that a reaction doubles in rate for every $10^\circ C$ increase in temperature. Considering the impact of a $10^\circ C$ increase in global temperature, would the same rule apply to kinetic weather processes - for example, would the average wind speed around the world double? |
It is well known that the A in both DNA and RNA stands for acid, but where is the acid in chemical formula for the compound, and it is classified so based on what acid-base theory? Like Arrhenius, Bronsted-Lowry or Lewis.
Just to better explain my question, when I say DNA I am essencially thinking about nucleotides ... |
Where is the acid in DNA/RNA? |
>Just to better explain my question, when I say DNA I am essencially thinking about nucleotides linked together, am I missing something in the structure that contains my answer or this is the way to go?
Yes, you do. *NA consist of nucleotides, linked by phosphodiester fragments. This leaves on hydroxyl of phosphate ... |
I bought a 2 pH meters several months back from Amazon for roughly $10 a piece. I couldn't tell you how they work, but here's the link on Amazon: http://www.amazon.com/gp/product/B0087LOWIA/ref=wms_ohs_product?ie=UTF8&psc=1
I also got a neutral buffer solution for calibration. It worked fine initially but I'm thi... |
So I know that the best Lewis Structure representation of sulfuric acid is one with only single bonds - i.e. sulfur isn't hypervalent.
However, why are the S-O and S-OH bonds not equivalent then? Why do their lengths differ?
I suspect this has something to do with the addition of the hydrogen on the oxygen atom... |
If I have a aqueous sulfuric acid solution as electrolyte and the anode electrode is made out of copper and the cathode electrode is made out of graphite, what are the two reactions at the respective electrodes and why? |
Consider the reversible unimolecular reaction:
$A \overset{k_{1}}{\underset{k_{2}}{\rightleftharpoons}} B$
We know that the forward reaction is often considerably more thermodynamically favourable than the reverse reaction, and therefore the relationship k1 >> k2 holds between the rate constants. The rate constan... |
Good questions, let's step through them one at a time.
1) "So I know that the best Lewis Structure representation of sulfuric acid is one with only single bonds - i.e. sulfur isn't hypervalent. "
Look at the resonance structures below. The one on the left with sulfur hypervalent is the only uncharged resonanc... |
What are some incapability that the earlier spectroscopy(Visible, Ultraviolet Violet and Infra-red) spectroscopy have when compare to the more modern method? |
What are some incapability that the early spectroscopy have when compare to the more modern method? |
If I have a aqueous sulfuric acid solution as electrolyte and the anode electrode is made out of copper and the cathode electrode is made out of graphite, what are the two reactions at the respective electrodes and why?
Anode: Cu → Cu2+ + 2e-
Cathode: 2e- + 2H+ → H2(g)
total: 2H+ + Cu → H2 + Cu2+
That should be... |
>Just to better explain my question, when I say DNA I am essencially thinking about nucleotides linked together, am I missing something in the structure that contains my answer or this is the way to go?
Yes, you do. *NA consist of nucleotides, linked by phosphodiester fragments. This leaves one hydroxyl of the phosp... |
I read some articles and journal about activated carbon and found problem about how the adsorbate could bind with the activated carbon. some said it is because the intramolecular forces (van der waals) and some said it is because of chemisorpsi. if chemisorpsi did play a part, what would the bind be?
and if the bondin... |
how does activated carbon bind the adsorbate? |
What are some incapabilities that the earlier spectroscopy (Visible, Ultraviolet and Infra-red) have when compared to the more modern method? |
What are some incapabilities that the early spectroscopy have when compared to the more modern method? |
If I have aqueous sulfuric acid solution as electrolyte and the anode electrode is made out of copper and the cathode electrode is made out of graphite, what are the two reactions at the respective electrodes and why?
Anode: $$\ce{Cu → Cu2+ + 2e-}$$
Cathode: $$\ce{2e- + 2H+ → H2(g)}$$
Total: $$\ce{2H+ + Cu → H... |
So I know that the best Lewis Structure representation of sulfuric acid is one with only single bonds - i.e. sulfur isn't hypervalent.
However, why are the $\ce{S-O}$ and $\ce{S-OH}$ bonds not equivalent then? Why do their lengths differ?
I suspect this has something to do with the addition of the hydrogen on t... |
For Magnesium Sulphate heptahydrate, again 6 waters coordinate the $\ce{Mg2+}$. The 7th water is hydrogen bonded, but not coordinated to the $\ce{Mg2+}$.
The crystal structure is published as [Refinement of the Crystal Structure of Magnesium Sulphate Heptahydrate (Epsomite) by Neutron Diffraction][1].
Magnesiu... |
For Magnesium Sulphate heptahydrate, again 6 waters coordinate the $\ce{Mg^{2+}}$. The 7th water is hydrogen bonded, but not coordinated to the $\ce{Mg^{2+}}$.
The crystal structure is published as [Refinement of the Crystal Structure of Magnesium Sulphate Heptahydrate (Epsomite) by Neutron Diffraction][1].
Ma... |
How can I reduce Crystallisation temperature of seed oil to be used in winter as biodiesel?
The glycerol has been removed from the oil, and white spirit is used to reduce its viscosity. |
How can I reduce Crystallization temperature of seed oil to be used in winter as biodiesel? |
If I have aqueous sulfuric acid solution as electrolyte and the anode electrode is made out of copper and the cathode electrode is made out of graphite, what are the two reactions at the respective electrodes and why?
Anode: $$\ce{Cu → Cu^{2+} + 2e-}$$
Cathode: $$\ce{2e- + 2H+ → H2(g)}$$
Total: $$\ce{2H+ + Cu ... |
I read some articles and journals about activated carbon and found a problem about how the adsorbate could bind to the activated carbon. Some said it is because of intramolecular forces (van der Waals) and some said it is because of chemisorption. If chemisorption plays a role, what would the bonding be?
And if the bo... |
How does activated carbon bind the adsorbate? |
I found this build-plan recycling on the internet (I believe it was originally published in a book written by the infamous clandestine chemist Hobart Huson) which seemed interesting to me. I do not have the money to pay for a professional fume hood, nor do I have the space to fit such thing. I have to switch the functi... |
I found this build-plan recycling on the internet (I believe it was originally published in a book written by the infamous clandestine chemist Hobart Huson) which seemed interesting to me. I do not have the money to pay for a professional fume hood, nor do I have the space to fit such thing. I have to switch the functi... |
In minerology class I was taught that metalic and ionic bonds are weaker than covalent bonds and that's why quartz and diamond have such a high hardness values. HOWEVER, in organic chemistry class I learned that covalent bonds are weaker than metalic and ionic bonds thus organic substances have a much lower melting poi... |
Are metalic/ionic bonds weaker than covalent bonds? I was taught the opposite. Now I'm confused |
In mineralogy class, I was taught that metallic and ionic bonds are weaker than covalent bonds and that's why quartz and diamond have such a high hardness value. However, in organic chemistry class, I learned that covalent bonds are weaker than metallic and ionic bonds, thus organic substances have a much lower melting... |
Are metallic/ionic bonds weaker than covalent bonds? I was taught the opposite. Now I'm confused |
>Is the thick plastic sheet enough the prevent most fumes from diffusing in my workplace?
Yes. Actually, you should care more about the integrity of the tube
>Is this plastic sheet a potential danger in case of fire?
Depends. But care more about inflammable and unmeltable working surface (metal or ceramic). S... |
If you do a little reading about fume cupboards, and in particular, benchtop extraction hoods, you will discover that they are constructed from materials not too dissimilar to your design; consider the difference being amateur use versus professional use. To address your four main concerns:
> Is the thick plastic sh... |
If you do a little reading about fume cupboards, and in particular, benchtop extraction hoods, you will discover that they are constructed from materials not too dissimilar to your design; consider the difference being amateur use versus professional use. To address your four main concerns:
> Is the thick plastic sh... |
How to calculate the number of moles present in a litre of saturated solution? |
Before I begin, I think it's worth mentioning that I know little about chemistry and even less about knifes. My question is this, having seen many people talk about how patinas work and the best ways of applying them and which ones are best etc, It seemed to me like people just assumed that they work, presumably becaus... |
Does a patina on a knife prevent rust? |
If I have a glass of water, and the vapor pressure is the point of equilibrium where the liquid molecules are becoming gases and the gas molecules are colliding and becoming liquid at the same rate, does that mean none of the liquid is lost? I feel as if I am misunderstanding this concept because when I leave my cup of... |
I would be interested to know people's opinion on the following matter.
**Background**
Often, when the far-from equilibrium behaviour of a chemical reaction system is analysed mathematically (in papers or text books), the system is placed in a gradient between a **fixed** non-zero concentration of "resource" spec... |
I would be interested to know people's opinion on the following matter.
**Background**
Often, when the far-from equilibrium behaviour of a chemical reaction system is analysed mathematically (in papers or text books), the system is placed in a gradient between a **fixed** non-zero concentration of "resource" spec... |
Suppose you have the following equation:
$$\ce{2NH4SCN(s) + Ba(OH)2(s) ->Ba(SCN)2(s) + 2H2O(l) + 2NH3(g)}$$
You initiate this reaction using 15.22g of the $\ce{NH4SCN}$ (and excess of the barium hydroxide) in a boiling tube resting in 50g of water. The temperature rises by 11 degrees. Therefore energy = $4.2 \tim... |
The electronic configuration for $Cu$, adjusted for Hund's rule, is:
$[Ar] 3d^{10} 4s^1$
So thus shouldn't $Cu$ have an oxidation number of $1^+$? whereby it gives off its outermost 4s electron? Why can it also have a $2^+$ charge? |
Why can $Cu$ have an oxidation number of $2^+$? |
Before I begin, I think it's worth mentioning that I know little about chemistry and even less about knives.
My question is this, having seen many people talk about how patinas work and the best ways of applying them and which ones are best etc., It seemed to me like people just assumed that they work, presumably b... |
The electronic configuration for $\ce{Cu}$, adjusted for Hund's rule, is:
$[\ce{Ar}] 3d^{10} 4s^1$
So, shouldn't $\ce{Cu}$ have an oxidation number of $+1$? whereby it gives off its outermost 4s electron? Why can it also have a $+2$ charge? |
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