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I have a question. When I was studying *Coordination Compounds*, I came across this para:
> When a sample absorbs light, what we see is the sum of remaining colors that strikes our eyes. Observed and absorbed colors are generally complimentary.
Now, I have doubt that does sample word applies to all the objects of uni... |
tM in Chromatography is the time of exist mobile phase. But, the mobile phase exist together with all the compunds that tasted in the process. So, why in the graph of signal to time we can see a peak separated from all the other ?
thanks,
Liat |
Chromatography- why tM is separated from other peaks? |
We say that a homogeneous sample consists of the chemically same type of molecules whereas heterogeneous ones vary chemically, i.e. the molecules throughout are not same and also not uniform.
Why do we treat a (water + water vapour) system as heterogeneous in spite of the presence of the same kind of molecules? Also... |
What does heterogeneous mean? |
I discovered recently that adding baking soda to a recipe can neutralize the strong flavours of the coconut oil. Does anyone know how it is working and what is, in a simple way, the chemical reaction for this?
Thank you very much. |
Why baking soda neutralize the flavor of coconut oil? |
If I have the reaction:
$2$HI (g) ⇌ H$_2$ (g) I$_2$ (g)
and know that at T = $448^o$C the dissociation constant α = $0.2198$. How do I calculate K$_c$?
I thought that it would be something like this:
$$
\begin{array}{c|c|c|c}
\style{font-family:inherit}{\text{$2$HI}} & \style{font-family:inherit}{\text{⇌ ... |
Consider the following rxns:
1. $\ce{C + O2->CO2}$
2. $\ce{2C + O2->2CO}$
3. $\ce{2CO + O2->2CO2}$
$[(2)+(3)]\div2$ yields $(1)$
Since ∆G is a state function so why don't the straight lines corresponding these rxns in the ellingham Diagram intersect at a point? |
This question might be a bit weird, but I just asked myself why a wooden cooking spoon creates bubbles when put in oil at about 170°C. This is a common trick to find out, if Oil has the right temperature for frying.
My idea is, that the water in the wooden spoon starts to evaporate, but why does this just start to hap... |
Why does a wooden spoon creates bubbles when put in hot oil? |
Consider the following rxns:
1. $\ce{C + O2->CO2}$
2. $\ce{2C + O2->2CO}$
3. $\ce{2CO + O2->2CO2}$
$[(2)+(3)]\div2$ yields $(1)$
[![Ellingham Diagram for Carbon][1]][1]
Since G is a state function so why don't the straight lines corresponding these rxns in the ellingham Diagram are concurrent?
I h... |
I am interested in synthesis of co2+h2o or co2+h2+o2. I searched if some companies do this. For example I found “Air co.” that makes ecological vodka from air and water. Also few research labs and universities managed to make glucose or ethanol from co2 and water. Can you name similar endothermic synthesis reactions? O... |
Can you name examples of endothermic synthesis reaction? |
I have the reaction:
$$C_2H_5OH(l) + CH_3COOH(l) ⇌CH_3COOC_2H_5(l) + H_2O(l)$$
and want to calculate how much ethylacetate is formed if I have $3$ mol of ethanol and $1$ mol of acetic acid. K = $4.12$
This is how I calculated this:
$$
\begin{array}{c|c|c|c}
\style{font-family:inherit}{\text{C$_2$H$_5$OH}... |
I have to run a reaction using N,N'-Dicyclohexylcarbodiimide and at room temperature, it is solid, but it's very hard to weigh. I know its melting point is around 40 degrees. Is it better to melt it and measure it as a liquid or is it no worth the struggle? I just don't want to have it in my hands anymore after reading... |
How to efficiently weight DCC (N,N'-Dicyclohexylcarbodiimide)? |
I need to do an alcohol bromination using PBr3 and I've never done this reaction before. Reading about PBr3 I found it is water/air-sensitive and the bottle I bought doesn't have a seal. So how am I supposed to manipulate it if I can't expose it to air? Just open the bottle and insert an Ar flow rapidly? Is there a mor... |
A [paper](https://www.sciencedirect.com/science/article/pii/0009898187900696?via%3Dihub) I found details treating glucose-1,6-bisphosphate with 6M HCl to produce glucose-6-phosphate. I'm curious why glucose-1-phosphate (and then even plain glucose) isn't formed instead? |
Why does acid hydrolysis of glucose-1,6-bisphosphate produce glucose-6-phosphate and not glucose-1-phosphate? |
Let's use the example $\ce{NaC_2H_3O_2}$ (sodium acetate).
It disassociates into $\ce{Na+}$ and $\ce{C_2H_3O_2-}$. Why is the sodium ion not react with water, but the acetate ion does?
How do you tell if a anion and cation of a salt will react in water (if placed in water)? |
What characteristics make a salt acidic or basic? |
Can you name examples of reactions that are endothermic and synthesis at the same time? Like what plants do they take heat and sunlight and they synthetize air and water into organic fuels such as glucose and ethanol. I found similar experiments made for carbon capture some call it reverse combustion, they take air and... |
Any examples of reactions where synthesis happens and are endothermic at the same time? |
FWIW my background is in physics and maths, but I am just starting a chemistry PhD (the last time I took a chemistry class was high school). I have only some background in representation theory, and only an abstract taste, as it was in a maths class (bonus: suggest a reasonable representation/group theory reference wit... |
I have the reaction:
$$C_2H_5OH(l) + CH_3COOH(l) ⇌CH_3COOC_2H_5(l) + H_2O(l)$$
and want to calculate how much ethylacetate is formed if I have $3$ mol of ethanol and $1$ mol of acetic acid. K = $4.12$
This is how I calculated this:
$$
\begin{array}{c|c|c|c}
\style{font-family:inherit}{\text{C$_2$H$_5$OH}... |
Can you name examples of reactions that are endothermic and synthesis at the same time? Like what plants do they take heat and sunlight and they synthetize air and water into organic fuels such as glucose and ethanol. I found similar experiments made for carbon capture some call it reverse combustion, they take air and... |
FWIW my background is in physics and maths, but I am just starting a chemistry PhD (the last time I took a chemistry class was high school). I have only some background in representation theory, and only an abstract taste, as it was in a maths class (bonus: suggest a reasonable representation/group theory reference wit... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
What does per-o- acetylated glucopyranoside mean?
Can you please break down the roots? |
What does per-o- acetylated glucopyranoside mean? |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
When we scale a half reaction in order to balance the number of electrons with the other half reaction, we do not change the intrinsic joules per coulomb (Volts) of the electrons.
So Fe2+ +2e- -------> Fe (s) E = -0.44V
means that the 2 electrons carry -0.44 Joules per coulomb of energy
If we double the react... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
A $\ce{Cr(s) | Cr^3+ || Cd^2+ | Cd(s)}$ galvanic cell has redox half reactions:
$$
\begin{align}
\ce{Cd^2+ + 2e- &-> Cd(s)} &\quad E^\circ &= \pu{-0.4 V}\tag{R1}\\
\ce{Cr^3+ + 3e- &-> Cr(s)} &\quad E^\circ &= \pu{-0.7 V}\tag{R2}
\end{align}
$$
Balanced reaction equation then is
$$\ce{3 Cd^2+ + 2 Cr(s) -> ... |
Why can the specific heat at constant Pressure ($C_p$) be used to calculate the change in enthalpy as $\text{d}H = C_p\text{d}T\newcommand{\d}{\text{d}}$ for processes that are not even at constant pressure?
I have $\d H = C_p\d T + V\d p$. Why do we neglect the $V\d p$ term? For gases, $V$ the specific volume, can ... |
If a solution of dissolved metals in aqua regia is heated in an open container and left to dry overnight, will the dissolved metal ions be carried by the evaporated solution or will it stay in the container?
I was trying to get a solution of dissolved metals in aqua regia for ICP measurement but my sample got dried ... |
Will the amount of solute change if the solution evaporates? Will the solvent carry the solute with it if it evaporates? |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
If we try to calculate it using the familiar algebraic method, we get +1 oxidation state for both Nitrogen atoms and that's what I found when I looked it up on the internet. But, I had tried to do it with the structure and that's where I got confused.
[![enter image description here][1]][1]
Now, bond from the middl... |
If we try to calculate the oxidation state of nitrogen in $\ce{N2O}$ using the familiar algebraic method, we get oxidation state $+1$ for both nitrogen atoms and that's what I found when I looked it up on the internet.
I tried to do it with the structure and that's where I got confused:
$$\ce{\overset{-}{N}=\over... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/5BwPa.jpg
I don't know the proper nomenclature of the compound, so I'll do my best to describe it.
A 3 membered carbon ring with a double bond to oxygen from one carbon and a double bond between the remaining carbon with a methyl group atta... |
What would be the product of this reaction? |
> Why is E$^\circ_\mathrm{cell}$ independent of molar coefficients (3,2)?
The cell potential is the potential an electron experiences; the coefficients of the equation have no bearing on this. When you use the cell potential to calculate the electrical work a cell does, you would multiply by the charge that is flowi... |
> $$CH_3OH(g) + NOCl(g) ⇌ CH_3ONO(g) + HCl(g)$$
> The volume of the container is $433$ cm$^3$, T = $50^o$C. Methanol was added until the pressure was $50.1$ mbar, then $0.059$g of NOCl was added. At equilibrium the partial pressure of NOCl is $27.6$ mbar.
> Calculate K
I tried to solve the problem as follow... |
> If we try to calculate the oxidation state of nitrogen in $\ce{N2O}$ using the familiar algebraic method, we get oxidation state $+1$ for both nitrogen atoms and that's what I found when I looked it up on the internet.
Well … you get an *average oxidation state*. This calculation arguably implicitly assumes that a... |
What does per-*O*-acetylated glucopyranoside mean?
Can you please break down the roots? |
What does per-O-acetylated glucopyranoside mean? |
I have the reaction:
$$\ce{C2H5OH(l) + CH3COOH(l) <=> CH3COOC2H5(l) + H2O(l)}$$
and want to calculate how much ethylacetate is formed if I have $\pu{3 mol}$ of ethanol and $\pu{1 mol}$ of acetic acid. $K = 4.12$
This is how I calculated this:
$$
\begin{array}{c|c|c|c}
\ce{C2H5OH} & \ce{CH3COOH} & \ce{<=>}... |
Us humans are still at best mediocre at predicting the outcome of chemical reactions. Even computers are at best a little bit better. If there is no literature on this compound (and Orthocresol commented that he found none), no experiment has likely been performed and we cannot be certain.
You *could* find a computa... |
> Why is E$^\circ_\mathrm{cell}$ independent of molar coefficients (3,2)?
The cell potential is the potential an electron experiences; the coefficients of the equation have no bearing on this. When you use the cell potential to calculate the electrical work a cell does, however, you would multiply by the charge that... |
Any examples of reactions where simpler molecules are combined into more complex ones and are endothermic at the same time? |
Can you name examples of reactions that are endothermic and simple molecules are combined into more complex ones at the same time? Like what plants do they take heat and sunlight and they synthetize air and water into organic fuels such as glucose and ethanol. I found similar experiments made for carbon capture some ca... |
> $$\ce{CH_3OH(g) + NOCl(g) ⇌ CH_3ONO(g) + HCl(g)}$$
> The volume of the container is $433$ cm$^3$, T = $50^o$C. Methanol was added until the pressure was $50.1$ mbar, then $0.059$g of NOCl was added. At equilibrium the partial pressure of NOCl is $27.6$ mbar.
> Calculate K
I tried to solve the problem as f... |
> $$\ce{CH_3OH(g) + NOCl(g) <=> CH_3ONO(g) + HCl(g)}$$
> The volume of the container is $433$ cm$^3$, T = $50^o$C. Methanol was added until the pressure was $50.1$ mbar, then $0.059$g of NOCl was added. At equilibrium the partial pressure of NOCl is $27.6$ mbar.
> Calculate K
I tried to solve the problem as... |
Can you name examples of reactions that are endothermic and simple molecules are combined into more complex ones at the same time? Like what plants do they take heat and sunlight and they synthetize air and water into organic fuels such as glucose and ethanol. I found similar experiments made for carbon capture some ca... |
While reading about Hydrogen bonding in a book *(O.P. Tandon's G.R.B. Organic Chemistry)*, I came across a sentence that was mentioned in a rather unstructured way relative to how comprehensive I was finding it until then.
[Here](https://i.stack.imgur.com/cDx1Z.png) is the excerpt of that.
_______
And here I quot... |
Why are Hydrogen bonds directional? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/QO39g.png
I know that the last two on the right are stable so they are not the answer, but can someone give me a hint on how to decide between the two on the left? what is the way of solving such question, I don't think it's only dependent... |
Which compound releases more energy upon combustion? |
My textbook [Chemistry Live, Declan Kennedy] states that ''Ethanol is said to be infinitely soluble in water''. It then says ''verify this for yourself by mixing some ethanol with water in a test tube''.
Both water and ethanol are colourless. How can I observe that they are infinitely soluble ? |
How to verify that ethanol is infinitely soluble in water? |
I'm learning about acid-base equilibria. I know that an (Bronsted-Lowry) acid donates a hydrogen proton, and a base donates a hydrogen proton, but I've also heard about a Lewis acid base theory, where electrons are the key difference. What's the point of making a even more general? And I'm not sure exactly what an salt... |
How do I tell the difference between an acid, base, and a salt solution? |
I'm learning about acid-base equilibria. I know that an (Bronsted-Lowry) acid donates a hydrogen proton, and a base donates a hydrogen proton, but I've also heard about a Lewis acid base theory, where electrons are the key difference. What's the point of making a even more general? And I'm not sure exactly what an salt... |
I have the delta T, I have the specific heat of the calorimeter, I have known weights/mass. I know the salt is lithium-based. What steps do I take to calculate the enthalpy of the solution so I can compare my answer to the specific molar enthalpies of possible lithium salts?
If the equation I use is Q=m x c x dt, wh... |
How do I go about calculating the enthalpy of a solution with an unknown salt? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/r7DEH.png
After this cyclic ether is activated with H+, will the bromide attack the more substituted site on the left or the less substituted side on the right? I think it will attack the right because SN2 favors less steric hindrance, b... |
Commonly, the empirical formula $\ce{N2O}$ refers to the molecule with structure $\ce{N\bond{~--}N\bond{~-}O}$. Is the isomer $\ce{N-O-N}$ known to exist? I'm guessing it is significantly less stable than the NNO isomer, but that doesn't mean it's completely unknown. |
Is N--O--N known to exist? |
I'm just going to put the questions first and the explanation after in case y'all don't have the patience.
I want to know if it's reasonable to think that :
1) Using an ultrasonic bath on something like a rotovap would prevent bumping, with the cavitation effects serving as basically the ultimate boiling chip.
... |
Degassing HI from Reaction (Via Ultrasound Maybe?) |
In a paramgnetic material the induced dipole moment of atoms or (molecules) of the material aligns with the external field. I can understand this by Zeeman splitting. A term symbol splits into states with different energy. According to Boltzmann distribution the lower energy states should have more population. These st... |
**Please edit the table to include missing data**
Avogadro constant in the "CRC Handbook of Chemistry and Physics"
| Edition | Years(s) | page | value | CODATA? |
|---------|-----------|-------|--------------|-------------------|
| 1 [(Link)](https://books.google.com/books?id=07AHIEp6vYQC&printse... |
Conducting an experiment, I found that very little salicylic acid was evolved performing hydrolysis at pH 2 and at 45 degrees C. In fact, far more salicylic acid was evolved at pH 7. This comes as a surprise to me because I expected an acid-catalyzed ester hydrolysis to actually quicken the rate of reaction and thereby... |
I am a high school student and I am very confused in salt hydrolysis
My confusion is that: when we talk of hydrolysis of salt of weak base and weak acid, we internally assume the degree of hydrolysis of both cation and anion of the salt is assumed to be same but I think it is a very wrong assumption, why don't we si... |
I am a high school student and I am very confused in salt hydrolysis
My confusion is that: when we talk of hydrolysis of salt of weak base and weak acid, we internally assume the degree of hydrolysis of both cation and anion of the salt is assumed to be same but I think it is a very wrong assumption, why don't we si... |
In polyelectronic atoms, the reduction in the net central force due to electron-electron repulsion is accounted for through an effective nuclear charge that depends on a “shielding effect” of inner electrons.
The reason for the splitting of energies of orbitals in the same quantum shell (s<p<d<f) is usually given t... |
Why are s orbitals more “penetrating” than p orbitals? |
I wonder, why does benzoic acid have a higher melting point than stearic acids? |
I wonder, why does benzoic acid have a higher melting point than stearic acid? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/5BwPa.jpg
A 3 membered carbon ring with a double bond to oxygen from one carbon and a double bond between the remaining carbon with a methyl group attached to one of the carbon is made to undergo acid catalyzed hydrolysis. What will be the p... |
I wonder, why does benzoic acid have a higher melting point than stearic acid?
Here is the data:
Benzoic acid melting point = 122.3 deg. Celsius
Stearic acid melting point = 69.3 deg. Celsius
I wood understand that organic acids can bond with both London dispersion forces (van der Waals) and hydrogen bonds (due... |
I wonder, why does benzoic acid have a higher melting point than stearic acid?
Here is the data:
Benzoic acid melting point = 122.3 deg. Celsius
Stearic acid melting point = 69.3 deg. Celsius
I do understand that organic acids can bond with both London dispersion forces (van der Waals) and hydrogen bonds (due t... |
From my textbook, it is stated that:
e.g. If we add a basic salt NaF, it will fully dissociate to give F-. Then if we add HF, since it is a weak acid, the high concentration of F- already present in solution shifts the equilibrium to the left, hence fewer H+ forms than expected so higher pH.
But can I explain lik... |
This question is about the magnetic quantum numbers and their corresponding orbital orientations, e.g., p<sub>x</sub>, d<sub>yz</sub>, etc. Are the electrons in any given subshell distributed across the orbitals in any particular order as the number of electrons increases? Such as m = -1 first, then m = 1, etc.?
|
Are electron orbital orientations filled in any particular order? |
Puzzles are more puzzling when the pieces *almost* fit together, but for some unexplained reason, just don't fit. In other words, a comparison should be made between two almost (but not quite) similar things.
In this case, stearic and benzoic acids are quite different. They have some carbons (quite different, and n... |
No, you cannot say that there is a particular order in which the shells are filled.
### Relation between $\mathrm{p_x,p_y,p_z}$ with $\mathbb{m_l}$ values ###
The magentic quantum number ${m_l}$ represents the projection of the angular momentum $\vec{l}$ of an electron in an orbital, on an axis, usually taken to ... |
Why should acetanilide be more soluble in water than benzoic acid when benzoic acid has the same number of h-bonding sites and has an ionizable site, allowing it to form ion-dipole forces while acetanilide can't be ionized? I don't see how the dipoles would be significantly different as to make acetanilide more soluble... |
Why is benzoic acid less soluble in water than acetanilide? |
I wonder, why does benzoic acid have a higher melting point than stearic acid?
Here is the data:
Benzoic acid melting point = 122.3°C
Stearic acid melting point = 69.3°C
I do understand that organic acids can bond with both London dispersion forces (van der Waals) and hydrogen bonds (due to the -COOH group). ... |
I wonder, why does benzoic acid have a higher melting point than stearic acid?
Here is the data:
Benzoic acid melting point = 122.3 °C
Stearic acid melting point = 69.3 °C
I do understand that organic acids can bond with both London dispersion forces (van der Waals) and hydrogen bonds (due to the -COOH group)... |
Why does rate of chemisorption decrease with increase in pressure? |
<b>Background</b><br>
Topiramate (TPM) is an anticonvulsive and antimigraine drug that is helps prevent or reduce the frequency of epileptic seizures and that is used as a prophylaxis of migraine. (Shank and Maryanoff, 2008)<br>
TPM not only inhibits kainate subtypes and α-amino-3-hydroxy-5-methylisoxazole-4-propi... |
<b>Background</b><br>
Topiramate (TPM) is an anticonvulsive and antimigraine drug that is helps prevent or reduce the frequency of epileptic seizures and that is used as a prophylaxis of migraine. (Shank and Maryanoff, 2008)<br>
TPM not only inhibits kainate subtypes and α-amino-3-hydroxy-5-methylisoxazole-4-pro... |
<b>Background</b><br>
Topiramate (TPM) is an anticonvulsive and antimigraine drug that is helps prevent or reduce the frequency of epileptic seizures and that is used as a prophylaxis of migraine. (Shank and Maryanoff, 2008)<br>
TPM not only inhibits kainate subtypes and α-amino-3-hydroxy-5-methylisoxazole-4-pro... |
<b>Background</b><br>
Topiramate (TPM) is an anticonvulsive and antimigraine drug that helps prevent or reduce the frequency of epileptic seizures and that is used as a prophylaxis of migraine. (Shank and Maryanoff, 2008)<br>
TPM not only inhibits kainate subtypes and α-amino-3-hydroxy-5-methylisoxazole-4-... |
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