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How is indigo carmine used in Lowenthal-Permanganate titration as a redox indicator? |
My reference book mentions that:
_Proteins and carbohydrates are both polymers; however, only
carbohydrates commonly form branched polymers. Glycogen and
cellulose are both carbohydrate polymers made up of glucose monomers;
glycogen is a highly branched polymer while cellulose is primarily
straight-chained._
... |
Why don't proteins form branched polymers? |
honestly I have seen a lot of problems with "NMR" spectrums,
I looked for this title in Charles Mortimer's general chemistry book,
but I didn't see any sort of data, can anyone unfold what does NMR spectrum consist of?
thank you very much
|
honestly, I have seen a lot of problems with "NMR" spectrums,
I looked for this title in Charles Mortimer's general chemistry book,
but I didn't see any sort of data, can anyone unfold what does NMR spectrum consist of?
thank you very much
|
Allright, guys. All I wanted happens to be stochastic simulation.
Here is the list of sample algorithms:
- Gillespie SSA - original.
- Tau-leaping - evaluate time step and then out of that reactions and substances amount.
- R-leaping - vise versa. Good for big systems with only a few relatively highly reactive... |
I'm calculating $\Delta G$, $\Delta H$ and $\Delta S$ when an ideal gas expands isothermally and reversible at $20$°C from $5$ MPa to $1$ MPa. I used the relation that:
$$\left(\frac{\partial G}{\partial P}\right)_T=V$$
This relation can be shown from the defintion $G=H-TS$. Then I integrated G so that:
$$\De... |
Isn't $dS=0$ when there is a reversible process? |
Isn't the change in entropy zero for a reversible process? |
I would like to ask how I could derive the entropy change $dS$ for a van der Waals' gas.
I think I would need to use the total differential of entropy and then use the Maxwell relation shown below.\
Firstly, I would write down the total differential for $S$.
$$dS = \left(\dfrac{\partial S}{\partial V}\right)_T dV + ... |
I would like to ask how I could derive the entropy change $dS$ for a van der Waals' gas.
I think I would need to use the total differential of entropy and then use the Maxwell relation shown below.\
Firstly, I would write down the total differential for $S$.
$$dS = \left(\dfrac{\partial S}{\partial V}\right)_T dV + ... |
Both can be A,a or e,e, in 1,4 the groups are further apart -> less steric strain, why is 1,4 less stable according to experimental values?
1,2 high energy conformer's relative energy (kj/mol) is 4.05
1,4 high energy conformer's relative energy (kj/mol) is 4.50
|
Why trans-1-chloro-4-methylcyclohexane have a higher relative energy than trans-1-chloro-2-methylcyclohexane? |
Both can be A,a or e,e, in 1,4 the groups are further apart -> less steric strain, why is 1,4 less stable according to experimental values?
1,2 high energy conformer's relative energy (kj/mol) is 4.05 and
1,4 high energy conformer's relative energy (kj/mol) is 4.50
|
If the two bromines are attached at opposite ends of the molecule, why are they both labelled with a 6?
Also, why is 6,6'-dibromoindigo not called 1,1'-dibromoindigo if carbons in a ring are numbered according to their substituents, and bromine is the substituent, therefore the carbon it is attached to should be c... |
Why is Tyrian purple called 6,6'-dibromoindigo if all carbons are numbered differently? And the bromines are at opposite ends? |
Cl is an electro negative element and hydrogen is electro positive element. Why is Bonding between H and Cl not considered as H bonding?I read it in a book but there was no reason given for it. |
Why is Bonding between H and Cl not considered as H bonding? |
My reference book (Princeton Review for SAT Chemistry Subject Test) mentions that:
_Proteins and carbohydrates are both polymers; however, only
carbohydrates commonly form branched polymers. Glycogen and
cellulose are both carbohydrate polymers made up of glucose monomers;
glycogen is a highly branched polymer wh... |
Following are the three different answers to this question that I reached by googling. Which of them is right?
<br/><br/>
1. The covalent bond between the 3' C and the O, and the covalent bond between the 5' C and the O:<br/>
[![enter image description here][1]][1]
<br/><br/>
2. The covalent bond between the P a... |
In the DNA backbone, which bonds exactly are considered ester bonds? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/L3nGr.jpg
I think the red numbering is correct, but in the answer key, they have used the blue numbering.
Which is correct?
My question is regarding selection of parent chain in an alcohol
While selecting the parent carbon chain (base name) ... |
How to balance the following chemical equation using Oxidation number method? |
I have a product, which according to the MSDS is mostly D-Limonene. I don't have the means to chemically test it, but I did try dissolving polystyrene with it. Before I come check it again, should I expect how polystyrene "dissolves" in acetone? As a goop at the bottom, even as I add much excess acetone? Or, should I s... |
In my textbook examples are only given for up to the third shell.
What about the fourth and fifth shell ?
I still get confused over the fact that the n=3 shell has 18 electrons yet for chemical purposes atoms seek out 8 electrons. My understanding is that the energy difference between the 3p and 3d orbitals are j... |
Does the octet rule only apply to the second and third shell or does it apply further? |
In my textbook examples are only given for up to the third shell.
What about the fourth and fifth shell ?
I still get confused over the fact that the n=3 shell has 18 electrons yet for chemical purposes atoms seek out 8 electrons. My understanding is that the energy difference between the 3p and 3d orbitals are j... |
An aldol is a $\beta$-hydroxy ketone or aldehyde, and is the product of an aldol addition.
The enzyme that cleaves the bond formed (red) is known as an aldolase. The transaldolase reaction begins by aldol cleavage that is, cleavage of the bond in... |
Cl is an electronegative element and hydrogen is electropositive. Why are intermolecular interactions involving H and Cl not considered as H bonding? I read it in a book but there was no reason given for it. |
I have learnt that temperature sort of indicates the internal energy of a system, or at least this is my intuition. So if temperature is constant, then internal energy is constant as well.
But in the derivation of the following formula
\begin{align}{
{\Delta H = \Delta U + \Delta n_g RT}}
\end{align}
T doesn't ... |
How is temperature constant in enthalpy change formula? |
Sorry if this is an obvious answer. I tried rewording this question every way I could, but search engines came up with nothing- they all skirted around this exact question.
Why do certain compounds, such as fatty acid or Vitamin A, dissolve in oil? Polar substances can dissolve in water because water molecules are... |
Why do certain compounds dissolve in oil? Why do some types of compounds dissolve in oil, yet not water? |
Sorry if this is an obvious answer. I tried rewording this question every way I could, but search engines came up with nothing- they all skirted around this exact question.
Why do certain compounds, such as fatty acid or Vitamin A, dissolve in oil?
Polar substances can dissolve in water because water molecules a... |
Sorry if this is an obvious answer. I tried rewording this question every way I could, but search engines came up with nothing- they all skirted around this exact question.
Why do certain compounds, such as fatty acid or Vitamin A, dissolve in oil?
Polar substances can dissolve in water because water molecules a... |
I propose a logical approach, to explain the rule "the like dissolve like". Why don't we admit that all liquids should be able to mix, exactly like gases may be mixed in all proportion ? This is the case for non polar molecules, like oils. And if two liquids don't mix, this is due to the existence of attracting forces ... |
>How to select the parent carbon chain for IUPAC naming of following compound?
>
>[![2-bromo-3,6-diethylnonan-5-ol][1]][1]
I think the red numbering is correct, but in the answer key, they have used the blue numbering.
Which is correct?
My question is regarding selection of parent chain in an alcohol. While... |
Sorry if this is an obvious answer. I tried rewording this question every way I could, but search engines came up with nothing- they all skirted around this exact question.
Why do certain compounds, such as fatty acid or Vitamin A, dissolve in oil?
Polar substances can dissolve in water because water molecules a... |
Using whole molecules as oxidizing or reducing agents is my favorite method for dealing with redox reactions where atomic oxidation numbers are not straightforward. Here we use ethanol as a reducing reagent. With that let us design our half reactions:
**Oxidation of ethanol to formate ion**
We suppose ethanol i... |
Using whole molecules as oxidizing or reducing agents is my favorite method for dealing with redox reactions where atomic oxidation numbers are not straightforward. Here we use ethanol as a reducing reagent. With that let us design our half reactions:
**Oxidation of ethanol to formate ion**
We suppose ethanol i... |
Using whole molecules as oxidizing or reducing agents is my favorite method for dealing with redox reactions where atomic oxidation numbers are not straightforward. Here we use ethanol as a reducing reagent. With that let us design our half reactions:
**Oxidation of ethanol to formate ion**
We suppose ethanol i... |
Using whole molecules as oxidizing or reducing agents is my favorite method for dealing with redox reactions where atomic oxidation numbers are not straightforward. Here we use ethanol as a reducing reagent. With that let us design our half reactions:
**Oxidation of ethanol to formate ion**
We suppose ethanol i... |
in thermodynamics, we learn that change in state function is independent of the path/process, and thus we can conveniently pick any arbitrary path that allows easier calculation. I'm TA'ing a class and found that it would be great to actually show students an example where that a *simpler* path can indeed be constructe... |
in thermodynamics, we learn that change in state function is independent of the path/process, and thus we can conveniently pick any arbitrary path that allows easier calculation. I'm TA'ing a class and found that it would be great to actually show students an example where that a *simpler* path can indeed be constructe... |
How to balance the reaction between ethanol and chlorine using oxidation number method? |
I know that formic acid will dehydrate upon heating to 100°C (under normal pressure) or adding sulfuric acid. What other catalysts can be used to induce this reaction? |
1. Activated alumina, silica, thoriated silica gel, phosphorus pentoxide-silica gel, aluminum phosphate, titanium dioxide
<sub>Catalytic Dehydration of Formic Acid, E. G. Graeber and D. S. Cryder
Industrial & Engineering Chemistry **1935** 27 (7), 828-831, DOI: [10.1021/ie50307a019][1]</sub>
<sub>Mecha... |
A 2% (weight %) solution of a salt with Mr = 190.6 g mol-1 was prepared at 25 0C. The density of the prepared solution was 1.00926 g cm-3. The density of water at 25 0C is 0.99707 g cm-3, and the density of the crystalline salt was 3.00845 g cm-3.
a) ) What is the molar volume of the crystalline salt?
**molar vol... |
I am not a chemist but I have a question regarding electrolytes in electrolysis.
I have done a lot of reading but cannot find the answer I'm looking for regarding Sodium Sulfate (or Sulfide)
I intend to clean a film off a Stainless Steel plate, so that will be my cathode.
For my Anode I will be using a Platinum ... |
I am not a chemist but I have a question regarding electrolytes in electrolysis.
I have done a lot of reading but cannot find the answer I'm looking for regarding Sodium Sulfate (or Sulfide)
I intend to clean a film off a Stainless Steel plate, so that will be my cathode.
For my Anode I will be using a Platinum ... |
Simply put, why can't you draw square planar molecules top down (so you don't have to use depth bonds)? |
Why are square planar molecules drawn from the side plane as opposed to the top plane? |
You can do that. For example, a Google Image search for ["cisplatin structure"](https://www.google.com/search?tbm=isch&q=cisplatin+structure) suggests that although the hashed + wedged depiction is more common, the four plain bonds depiction is also in regular use.
For more detail on what's "acceptable" or not, refe... |
From the Wikipedia entry on Cyhalothrin:
Pyrethroids such as cyhalothrin are often preferred as an active ingredient in agricultural insecticides because they are more cost-effective and longer acting than natural pyrethrins. λ-and γ-cyhalothrin are now used to control insects and spider mites in cr... |
What do lowercase gamma and lowercase lambda mean in organice chemistry? In terms of isomers, presumably? |
What do γ (gamma) and λ (lambda) mean in organic chemistry? |
How would you draw a reaction coordinate diagram for an SN1 mechanism with the following conditions?
- each step in the mechanism (there are 2 steps) is favorable
- the second step of the mechanism is the rate-limiting step
I believe the RC diagram should look some thing like this, but I am not completely sure.
... |
How to draw a reaction coordinate diagram for SN1 mechanism? |
My professor posed my organic chemistry class a challenge problem for bonus points and I've been racking my brain over the last three days trying to work it out and I want to know if my solution is plausible. The problem asks us to draw the best curved arrow mechanism for the reaction in the bottom left corner of the p... |
Mechanism of acid-catalyzed Robinson annulation? |
Is there a simple reaction to yield boric acid (${H}_{3}{BO}_3$) from boron trifluoride $BF_3$? Thanks in advance. |
I am not a chemist but I have a question regarding electrolytes in electrolysis.
I have done a lot of reading but cannot find the answer I'm looking for regarding Sodium Sulfate (or Sulfide)
I intend to clean a film off a Stainless Steel plate, so that will be my cathode.
For my Anode I will be using a Platinum ... |
Is there a simple reaction to yield boric acid ($\ce{H3BO3}$) from boron trifluoride ($\ce{BF3}$)? |
>A solution is $\pu{0.10 M}$ $\ce{Ba(NO3)2}$ and $\pu{0.10 M}$ $\ce{Sr(NO3)2}$. If solid $\ce{Na2CrO4}$ is added to the solution, what is the $\ce{[Ba+]}$ when $\ce{SrCrO4}$ begins to precipitate? <br/> $\mathrm{K_{sp}}=\pu{1.2 \times 10^{-10}} \text{ for } \ce{BaCrO4}$<br/>
$\mathrm{K_{sp}}=\pu{3.5 \times 10^{-5}} \t... |
I am not a chemist but I have a question regarding electrolytes in electrolysis.
I have done a lot of reading but cannot find the answer I'm looking for regarding Sodium Sulfate (or Sulfide)
I intend to clean a film off a Stainless Steel plate, so that will be my cathode.
For my Anode I will be using a Platinum ... |
So I know that cathode is made of pure metal and anode of impure. For example take Cu. Cu will be oxidised to Cu+2 at anode and will deposit at cathode.
But now if it contains impurity of , let's say, Zn (even if that doesn't occur in nature just consider hypothetically) then won't Zn be oxidised at anode instead of C... |
Can a metal which contains impurity of another metal that is more reactive than itself be electrorefined? |
It is supposed addition of solid $\ce{Na2CrO4}$ would cause negligible volume change, so we can afford to consider the same $[\ce{Sr^2+}]$ as the initial one.
The task is rather theoretical, supposing the time point when $\ce{[Sr^2+][CrO4^2-]}$ just reached $K_\mathrm{sp,\ce{SrCrO4}}$, while $K_\mathrm{sp,\ce{SrCrO4... |
2-Acetylaminofluorene is a solid, mp 192-196 C. It satisfies the definition of being a VOC by virtue of being a compound of carbon, not excluded by the definition. It could be fine enough to be classified as PM 2.5 or 10 if it is powdered; more information would be necessary about the source of the compound. It is also... |
I am currently looking at the mechanism of the formation of storage deposits in jet fuel. Interestingly, the concentration of acids in the fuel correlates strongly with the total insolubles formed over testing periods. As such, several papers propose acid catalysed deposition processes occurring. However, since jet fue... |
Best way of studying protonation in non-polar solutions with ~100ppm of water present using DFT methods? |
Best way of studying protonation in non-polar solutions with ~100ppm of water present using computational methods? |
Before we begin, there is an implicit assumption that there is not a significant change in the volume of the solution by either adding $\ce{Na2CrO4}$ nor the precipitation of the $\ce{BaCrO4}$.
> First of all, in equation $(1)$ why did they put $\ce{[Sr^2+]}$ same as the initial concentration (before the addition o... |
Before we begin, there are two implicit assumptions:
* That there is not a significant change in the volume of the solution by either adding $\ce{Na2CrO4}$ nor the precipitation of the $\ce{BaCrO4}$
* That concentrations can be used instead of activities.
> First of all, in equation $(1)$ why did they put $\ce{[S... |
In my textbook, examples for the octet rule are only given for up to the third shell.
What about the fourth and fifth shell?
I still get confused over the fact that the $n=3$ shell has 18 electrons yet for chemical purposes atoms seek out 8 electrons. My understanding is that the energy difference between the 3p ... |
How can we prove the inequality Tds>dU+PdV? |
Does potential increase or decrease when covalent bonds are formed or broken? |
Does potential energy of molecules increase or decrease when covalent bonds are formed or broken? |
I will be using an approach which has been enlisted in the following book for answering this question: [Arrow Pushing in Inorganic Chemistry ;A Logical Approach to the Chemistry of the Main-Group Elements](https://onlinelibrary.wiley.com/doi/book/10.1002/9781118924525)
To start off, please go through my answer to t... |
My sir told me that when bonds are formed or broken , average separation between particles comes closer or decreases when they are broken.I see there is a lot of change in K.E but how is there change in P.E is not what I am able to understand.My sir also told that in case of liquids , P.E would be less as compared to g... |
How exactly should we combine three orbitals when we have three orbitals that are of correct symmetry to interact?
Take H2O for example. 2s,2pz and the A1 group (H2) orbitals can interact. It would seem trivial that the lowest bonding orbital is 2s in phase with A1, but what about the anti binding orbital? Most reso... |
I am confused about what seems to me two very different explanations for the relativistic contraction of orbitals for heavy elements.
My teacher told me that since 1s electrons in heavy elements travel very fast their momenta is much larger than predicted by classical physics. Hence the 1s orbital contracts lead to... |
I've heard this combination can be particularly effective at cleaning biofilms, perhaps because the TSP is a surfacant, allowing bleach to attach more layers of the biofilm.
However, I'm also aware one should be cautious when mixing anything other than water with bleach, as there are a wide variety of reactions that... |
Is it safe to combine sodium hypochlorite (bleach) sodium triphosphate (TSP) for cleaning? |
Consider the following organic compounds:
[![(1) 1-methylcyclohexa-1,4-diene; (2) 1-methylcyclohexa-1,3-diene; (3) 1,4-dimethylcyclohexa-1,4-diene][1]][1]
[1]: https://i.stack.imgur.com/ZW6kL.png
Compound $(1)$ has two double bonds, which I'll label $C1$ and $C4$ such that the methyl group is attached to $C1... |
How can we prove the inequality TdS > dU + pdV? |
How exactly should we combine three orbitals when we have three orbitals that are of correct symmetry to interact?
Take $\ce{H2O}$ for example. $\mathrm{2s},$ $\mathrm{2p}_z$ and the $A_1$ group $(\ce{H2})$ orbitals can interact. It would seem trivial that the lowest bonding orbital is $\mathrm{2s}$ in phase with $A... |
[![This is the question][1]][1]
[1]: https://i.stack.imgur.com/6JK6s.jpg
Now I Know that there is cyclic Ketal or cyclic acetal is formed when carbonyl compound reacts with Ethylene Glycol. But I am confused here because I am unable to decide what will be the major product formed here because there are two possib... |
> [![4‐oxopentanal → ethylene glycol][1]][1]
I Know that there is cyclic ketal or cyclic acetal is formed when carbonyl compound reacts with ethylene glycol. But I am confused here because I am unable to decide what will be the major product formed here because there are two possibilities, i.e. cyclic ketal and cyc... |
I was trying to identify the material of this sediment filter cap whether it is really Polypropylene but i couldnt get a good signal but only noises no matter the exposure and time (my raman spectrometer is 532nm.
[![enter image description here][1]][1]
Is it really hard to get raman signal out of black matte obj... |
I've heard this combination can be particularly effective at cleaning biofilms, perhaps because the TSP is a surfacant, allowing bleach to "attack" more layers of the biofilm.
However, I'm also aware one should be cautious when mixing anything other than water with bleach, as there are a wide variety of reactions th... |
Possibly. Let's say your reaction is
$$\ce{D -> E}$$
You inhibitor could catalyse an additional reaction
$$\ce{C <-> D}$$ (how do i do equillibrium arrows here?)
If the equillibrium of that reaction was well on the left side, that would slow down the original reaction quite a bit.
Alternatively, it could... |
There's no "steel" in that stuff. It is simply filled with inorganic particles, probably (partly?) iron dust. I'm using that stuff too. Quick test with a bar magnet showed the tube with the "steel" component as well as the cured epoxy are indeed slightly ferromagnetic.
Most importantly, i believe, this reduces macr... |
There's no "steel" in that stuff. It is simply filled with inorganic particles, probably (partly?) iron dust. I'm using jbweld too. Quick test with a bar magnet showed the tube with the "steel" component as well as the cured epoxy are indeed slightly ferromagnetic.
Most importantly, i believe, the filler reduces ma... |
I was searching on the internet whether cyclopropene is aromatic or not. I found out that the electrons are not delocalized, causing the molecule to be non-planar and so forth, a lot of reasons.
But I don't know why I just don't seem to fall for it. My question is, if there are 4n+2 pi electrons, why aren't they del... |
Why aren't the pi electrons delocalized in cyclopropene? |
This is the raman spectrum of the black cap:
[![enter image description here][1]][1]
I was expecting it to be Polypropylene but the peaks didn't match in wave numbers. Anyone got idea what kind of plastic has that peaks on the side of 1500?
[![enter image description here][2]][2]
When I tried the raman ... |
If I add phosphorus pentoxide to formic acid at atmospheric pressure and 20°C will they react? At what rate will CO be produced?
I have not been able to find a reference discussing this. |
Do formic acid and phosphorus pentoxide react at room temperature? |
I have come across H NMR spectrum of 1,4-dichlorobutane and I have noticed that signals there are different to what I would intuitively expect. Instead two triplets there are two multiplets of more complicated structure. I wonder why that is. Looks to me like some higher order spectrum, but I'm not sure. I don't think ... |
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