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What is the specific gravity of $\ce{H2O2}$ bleached viscose? In literature, I can find that this is $1.52~\mathrm{g~cm^{-3}}$, but for bleached viscose is it not findable. Can I presume $\ce{H2O2}$ treated viscose has the same density? |
A little context: I make craft chili oils for friends and family. I use a two-step infusion process. First, I infuse the oil for flavor by simmering spices in the oil held around 250 degrees Fahrenheit. Second, I add dried chili flakes into the flavored oil around 250 degrees Fahrenheit. I have used canola and grapesee... |
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... |
In my book is given the mechanism of HBr forming and I understand every step of it. We did the calculations of the rate of each reaction, which is easy depending on the sign (-,+) of compounds formed or spent, and knowing those rates we were finally able to find the rate of HBr which is well defined by the ***empirical... |
Besides mercury, what other non water-based substances are liquid at room temperature? What about Mixtures? |
Besides mercury, what other non water-based substances are liquid at room temperature? What about mixtures? |
If we take a look at the electromagnetic specter, microwave wavelength is higher than infrared, which means its *energy is very small*. To break chemical bonds, the energy required is 100-1000 kJ/mol, and this kind of energy can be afforded only by UV and VIS. Due to this, we can conclude that microwave radiation has ... |
Is microwave dangerous? |
In my book is given the mechanism of $\ce{HBr}$ forming and I understand every step of it. We did the calculations of the rate of each reaction, which is easy depending on the sign (-,+) of compounds formed or spent, and knowing those rates we were finally able to find the rate of $\ce{HBr}$ which is well defined by th... |
If we take a look at the electromagnetic specter, microwave wavelength is higher than infrared, which means its *energy is very small*. To break chemical bonds, the energy required is 100-1000 kJ/mol, and this kind of energy can be afforded only by UV and VIS. Due to this, we can conclude that microwave radiation has ... |
Is a microwave oven dangerous? |
I was thinking about liquids, and I started to wonder theses related questions:
1) Besides mercury, what elements are naturally liquid at room temperature?
2) What naturally found family of substances/mixtures that do not contain $\ce{H2O}$ are naturally liquid at room temperature? |
What elements and/or substances without water are liquid at room temperature? |
If we take a look at the electromagnetic specter, microwave wavelength is higher than infrared, which means its *energy is very small*. To break chemical bonds, the energy required is 100-1000 kJ/mol, and this kind of energy can be afforded only by UV and VIS. Due to this, we can conclude that microwave radiation has ... |
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 i... |
What is the product of a copper and vinegar reaction? |
Note Kevin's comment on another answer. The key observation here is that it is not a question of whether $\ce{NaCl}$ vaporises but whether there is a temperature range in which water vaporises and $\ce{NaCl}$ doesn't, the answer to which question is yes. The wider the gap between the solvent and the solute, the easier ... |
A TA talked about this today in the context of ketones.
If you stick a acetone and NaBH4 together, you get 2-propanol.
If you stick acetone and NaH together, you get an enolate. What's the difference? They're both hydrides. |
Why does a hydride like NaH act as a base, but a hydride like NaBH4 act as a nucleophile? |
A TA talked about this today in the context of ketones.
If you stick a acetone and NaBH4 together in a protic solvent, you get 2-propanol.
If you stick acetone and NaH together, you get an enolate. What's the difference? They're both hydrides. |
A TA talked about this today in the context of ketones.
If you stick an acetone and $\ce{NaBH4}$ together in a protic solvent, you get 2-propanol.
If you stick acetone and $\ce{NaH}$ together, you get an enolate. What's the difference? They're both hydrides. |
In titration we usually take burette reading upto 0.01 ml but my teacher says that
we need to take reading upto 0.05 ml.What does that mean.Does it mean if we get reading 23.56 we will record it as 23.60 and if we get 23.44 we record it as 23.40? |
For example ink on paper: how can I confirm that the bonding is van der Waals and not covalent? Similarly, the same question can be asked about other interaction such as hydrogen bonding, ionic bonding, etc.
Are there analytical or spectroscopic methods for this purpose? |
How to confirm the type of bonding taking place between two substances? |
I can think of any other way to influence the value of $\Delta G$ than (1) change the temperature (2) providing an external source to overcome the negative cell potential
The relationship between $\Delta G$ and $E_{\mathrm{cell}}$ is **$\Delta G =-nFE_{\mathrm{cell}}$**
Between $\Delta H$, $\Delta S$ and $\Delta ... |
In titration we usually take burette reading upto $0.01~\mathrm{mL}$, but my teacher says that we need to take reading up to $0.05~\mathrm{mL}$. What does that mean? Does it mean if I read $23.56~\mathrm{mL}$ that I should record it as $23.60~\mathrm{mL}$ and if I read $23.44~\mathrm{mL}$ I should record it as $23.40~\... |
What does it mean to take reading up to 0.05 mL? |
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 density functional ... |
How can I calculate the charge distribution of a water molecule? |
I was given the first structure, and then drew the other 5 resonance structures.
![resonance structures of 1-(cyclopenta-2,4-dien-1-ylidene)-N,N-dimethylmethanamine][1]
First of all, are they correct? ChemBioDraw had some complaints, but as far as I can see there's the same amount of electrons, and no valence o... |
How to rationalise the resonance structures and hybridisation of the nitrogen in a conjugated amine? |
I'm having trouble making sense of this answer. I believe I am doing all the steps right, but my main concern is that I am not arriving at a whole number. If my answer is correct, should I just round up or down?
Question
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> By using the known values of $\chi$ for $\ce{HgCo(NCS)4}$ calculate the number of unpair... |
I found a [thread][1] which discussed this which totally confused me. (refer to the part of the link which talks about $\ce{sp^2/sp^3}$)
The question "http://chemistry.stackexchange.com/questions/4390/" is helpful, but doesn't have aniline specifically. I understand that if the lone pair is in resonance, it becomes ... |
Is nitrogen of aniline sp² or sp³ hybridized? |
I'm having trouble making sense of this answer. I believe I am doing all the steps right, but my main concern is that I am not arriving at a whole number. If my answer is correct, should I just round up or down?
Question
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> By using the known values of $\chi$ for $\ce{HgCo(NCS)4}$ calculate the number of unpair... |
Its known that the only method to determine mercury in atomic absorbtion spectroscopy is the *cold vapor method*.
What is the reason that mercury can't be determined with other methods, such as flame, electrothermal AAS or even emission spectroscopy ? |
I'm having trouble making sense of this answer. I believe I am doing all the steps right, but my main concern is that I am not arriving at a whole number. If my answer is correct, should I just round up or down?
Question
---
> By using the known values of $\chi$ for $\ce{HgCo(NCS)4}$ calculate the number of unpair... |
Disclaimer: I am not a chemist
I was just drinking my Ice Age mineral water which is 'untouched since the Ice Age' and wondered if the bonds formed in each molecule have remained intact for all those years.
In a liquid that is just lying there underground I'm guessing that there is some, if not very energetic, mo... |
How long do the bonds in a molecule hold under nominally stable conditions? |
The [Wikipedia][1] page has this:
>Ethoxylation is an industrial process in which ethylene oxide is added to alcohols and phenols to turn it into a surfactant.
How does the reaction proceed?
**EDIT**: The answer to the [question][2] regarding epoxide rings reacting with bases does not include alcohols, and ... |
Is it possible that blowing on water (hot/cold) can cause a reaction between the $\ce{CO2}$ from expiration and the water, to form $\ce{H2CO3}$? Is $\ce{H2CO3}$ dangerous? |
Formation of carbonic acid from breath? |
I have searched Google for this but cannot seem to find an explanation. My question is as follows - what is the Chemistry/Biochemistry behind cis and trans fatty acids resulting in "Bad" LDL and "Good" HDL cholesterol? Is one synthesised favourably with cis/trans fatty acids as precursors?
I am under the impression... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/LyrlH.jpg
**ATTEMPT:-**MeO- preferably gives SN2 OR E2, being a strong base and good nucleophile. But which reaction proceeds in this case? |
what will be the compound A as the product? |
The [Wikipedia][1] page says this:
>Ethoxylation is an industrial process in which ethylene oxide is added to alcohols and phenols to turn it into a surfactant.
How does the reaction proceed?
The answer to the question "http://chemistry.stackexchange.com/questions/27288/" regarding epoxide rings reacting wi... |
What is the mechanism of the uncatalysed epoxide opening with alcohols? |
Say I have a CIF file describing some material in terms of its symmetry space group, lattice parameters and in-cell atom positions. A simple example might be,
data_global
_chemical_name 'Graphene'
_cell_length_a 2.46
_cell_length_b 2.46
_cell_length_c ... |
How to determine the Bravais lattice and atom basis vectors from a CIF file? |
How can the dipole moment of carbon monoxide be rationalised by molecular orbital theory? |
Water retention is how much water the fibre can retain. Water holding is function of hydrophilicity and construction of the fibre (fabric). What is the difference between those two? Because to retain is also to hold, in my knowledge. |
What is the difference between moisture regain and water holding capacity? |
Can chemicals change crystal structure by only touching? |
Why is no bromine liberated in the reaction of potassium bromide and concentrated phosphoric acid? |
> But I don't understand why - shouldn't more protons in the environment lead to faster protonation of the carbonyl oxygen of acetic anhydride? Could you please explain it to me?
The short answer is "side reactions". Without more information about your exact experimental conditions, or even better, data about the o... |
I just had a question in a test asking to compare the relative acidity of picric acid (TNP) and carbonic acid, $\ce{H2CO3}$ (not phenol). It turns out that TNP is more acidic. 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 have been told that al... |
There is another closely related post [here][1] , and I've also read the referenced wiki article including applications of chelation, but I still don't see what's so special about chelation. I understand the structure of the bond - the 'capturing' of a metal cation by an organic agent, but I still fail to see why this ... |
What's so special about chelation? |
I've done a student experiment using cyclohexanol to prepare cyclohexene.
We mix 10.5g cyclohexanol and 5mL 85% $\ce{H3PO4}$ in a 50mL flask, then distillate while heating.
I want to know during this process what kind of side reaction happens because I notice there is something light yellow in the flask. After re... |
What happens when I use cyclohexanol to prepare cyclohexene? |
I've done a student experiment using cyclohexanol to prepare cyclohexene.
We mix 10.5g cyclohexanol and 5mL 85% $\ce{H3PO4}$ in a 50mL flask, then distillate while heating.
I want to know during this process what kind of side reaction happens because I notice there is something light yellow in the flask. After re... |
I've done a student experiment using cyclohexanol to prepare cyclohexene.
We mix 10.5g cyclohexanol and 5mL 85% $\ce{H3PO4}$ in a 50mL flask, then distillate while heating.
I want to know during this process what kind of side reaction happens because I notice there is something light yellow in the flask. After re... |
I've done a student experiment using cyclohexanol to prepare cyclohexene.
We mix 10.5g cyclohexanol and 5mL 85% $\ce{H3PO4}$ in a 50mL flask, then distill while heating.
I want to know during this process what kind of side reaction happens because I notice there is something light yellow in the flask. After react... |
all. This is my first question, so if I don't properly observe any conventions, my apologies!
Every chemistry textbook I have ever seen defines intensive and extensive properties the same way: Intensive properties are those which do not depend on how much matter is present, while extensive properties do. I came acro... |
Good day, all. This is my first question, so if I don't properly observe any conventions, my apologies! (Semi-related: Does anyone know why SE keeps removing the word "Hello" when I try to make it the first word of my post?)
Every chemistry textbook I have ever seen defines intensive and extensive properties the sam... |
Every chemistry textbook I have ever seen defines intensive and extensive properties the same way: Intensive properties are those which do not depend on how much matter is present, while extensive properties do. I came across a question while looking through sample FE exam questions for which my understanding of thes... |
If you are asking about the water molecules themselves (and not some other materials present such as the paleochemical structure above) the answer is that at least for liquid water, each water molecule exchanges its hydrogen atoms with other water molecules at an extremely rapid pace (millions of times per second). Whi... |
Here is my question,
What volume of a concentrated HCL solution, which is 36.0% HCL by mass and has a density of 1.179g/ml, should be used to make 5.00L of an HCL solution with a pH of 1.8.
----------
My Method:
- I found the respective volumes that H20 and HCL contrubuted
- I then found the Molarity of ... |
Here is my question,
What volume of a concentrated HCL solution, which is 36.0% HCL by mass and has a density of 1.179g/ml, should be used to make 5.00L of an HCL solution with a pH of 1.8.
----------
My Method:
- I found the respective volumes that H2o and HCL contrubuted
- I then found the Molarity of ... |
Here is my question,
> What volume of a concentrated $\ce{HCl}$ solution, which is 36.0% $\ce{HCl}$ by mass
> and has a density of 1.179g/ml, should be used to make 5.00L of an $\ce{HCl}$
> solution with a pH of 1.8.
----------
My Method:
- I found the respective volumes that $\ce{H2O}$ and $\ce{HCl}$ co... |
Here is my question,
> What volume of a concentrated $\ce{HCl}$ solution, which is 36.0% $\ce{HCl}$ by mass
> and has a density of 1.179g/ml, should be used to make 5.00L of an $\ce{HCl}$
> solution with a pH of 1.8.
----------
My Method:
- I found the respective volumes that $\ce{H2O}$ and $\ce{HCl}$ co... |
Here is my question:
> What volume of a concentrated $\ce{HCl}$ solution, which is $36.0\%$ $\ce{HCl}$ by mass
> and has a density of $1.179~\mathrm{g~mL^{-1}}$, should be used to make $5.00~\mathrm{L}$ of an $\ce{HCl}$
> solution with a $\mathrm{pH}$ of $1.8$.
----------
My Method:
- I found the respect... |
I've done a student experiment using cyclohexanol to prepare cyclohexene.
We mix $10.5~\mathrm{g}$ cyclohexanol and $5~\mathrm{mL}$ $85\%$ $\ce{H3PO4}$ in a $50~\mathrm{mL}$ flask, then distill while heating.
I want to know during this process what kind of side reaction happens because I notice there is something... |
How would we use our $\mathrm{p}K\text{a}$ of the acid component of the buffer to calculate $\dfrac{[\ce{A-}]}{[\ce{HA}]}$?
I know $$\mathrm{pH} = \mathrm{p}K\text{a} + \log_{10}\left(\dfrac{[\ce{A-}]}{[\ce{HA}]}\right)$$ rearranging gives me $$\log_{10}\left(\dfrac{[\ce{A-}]}{[\ce{HA}]}\right)=\mathrm{pH} - \mathrm... |
I was wondering what salts of gold are soluble and which are insoluble. From what I understand, silver is soluble as silver nitrate but insoluble as most other common salts like chlorides and sulphates. How does this work with gold? I was also wondering if there are any rules for solubility of salts, or whether there i... |
Solubility of gold salt solution? |
I know I should divide $\mathrm{g~L^{-1}}$ by the molar mass of the substance, but I don't seem to find the specific answer on Google. So just to be sure :
If I have $10^{-5}~\mathrm{g~L^{-1}}~\cf{Cu^{2+}}$ solution, do I have $1.57 \times 10^{-7}~\mathrm{mol~L^{-1}}$?
I think I'm missing something.
|
I know I should divide $\mathrm{g~L^{-1}}$ by the molar mass of the substance, but I don't seem to find the specific answer on Google. So just to be sure:
If I have $10^{-5}~\mathrm{g~L^{-1}}~\cf{Cu^{2+}}$ solution, do I have $1.57 \times 10^{-7}~\mathrm{mol~L^{-1}}$?
I think I'm missing something.
|
How would we use our $\mathrm{p}K_{\mathrm{a}}$ of the acid component of the buffer to calculate $\dfrac{[\ce{A-}]}{[\ce{HA}]}$?
I know $$\mathrm{pH} = \mathrm{p}K_{\mathrm{a}} + \log\left(\dfrac{[\ce{A-}]}{[\ce{HA}]}\right)$$ rearranging gives me $$\log\left(\dfrac{[\ce{A-}]}{[\ce{HA}]}\right)=\mathrm{pH} - \mathrm... |
> But I don't understand why - shouldn't more protons in the environment lead to faster protonation of the carbonyl oxygen of acetic anhydride? Could you please explain it to me?
The short answer is "side reactions". Without more information about your exact experimental conditions, or even better, data about the o... |
Recently I had to make some research about $\ce{Ca(OH)_2}$ and I find this on wikipedia :
![enter image description here][1]
Can you explain my why solubility decrease when temperature grows up ?
[1]: https://i.stack.imgur.com/WXF1y.png |
Why solubility doesn't increase when temperature grows up? |
What is the difference between the esterification and transesterification? |
In short, for this group 2 hydroxide crystal, the dissolution and solvation process is an exothermic equilibrium. Increasing the temperature drives the reaction in the reverse, favouring crystallisation!
However, it would be nice to rationalise some of these terms, so I will lay out a very brief overview of general... |
Recently I had to make some research about $\ce{Ca(OH)_2}$ and I found this on wikipedia :
![enter image description here][1]
Can you explain my why solubility decreases when temperature increases?
[1]: https://i.stack.imgur.com/WXF1y.png |
Why solubility decreases with temperature increase? |
What is the value for the reverse reaction? |
The problem I keep getting incorrect is What is the freezing point of water made by dissolving 10.11 g of magnesium chloride in 86.03 g of water? The freezing-point depression constant of water is 1.86 oC/m.
To start I take the 10.11g MgCl/(86.03*1/1000)(1.86 oC/m), which I keep getting 63.18oC.
What am I doing wro... |
Why/How am I calculating freezing point depression wrong? |
The problem I keep getting incorrect is What is the freezing point of water made by dissolving 10.11 g of magnesium chloride in 86.03 g of water?
The freezing-point depression constant of water is 1.86C/m.
To start I take the $\frac{10.11g\ \ce{MgCl}}{(86.03 \times 1/1000)(1.86C/m)}$, which I keep getting 63.18... |
${K_c}$ of reverse reaction should just be the reciprocal of forward ${K_c}$. So, ${K_c}$ of reverse reaction is ${1/1752}$. Now, I am not sure, why you used 2nd equation. Suppose you have 1 unit conc of ${NO}$ and ${O_2}$, then after time t, if the conversion is x, then your equation should be
${1752=[2x]^2/([1-x])... |
${K_c}$ of reverse reaction should just be the reciprocal of forward ${K_c}$. So, ${K_c}$ of reverse reaction is $\frac{1}{1752}$.
Now, I am not sure, why you used 2nd equation. Suppose you have 1 unit conc of $\ce{NO}$ and $\ce{O_2}$, then after time $t$, if the conversion is $x$, then your equation should be
$... |
What is the necessary volume of concentrated HCl to prepare a solution with a pH of 1.8? |
I Have 2 soluble salts in aqueous distilled water solution. I know that one of the salts is K2SO4 and I know that the anion of the second salt is Cl-. I know that the second salt is either MgCl2, NaCl, CaCl2, or KCl. I tested for the anion for the second salt by adding AgNO3 into the solution and observing a white prec... |
I have 2 soluble salts in aqueous distilled water solution. I know that one of the salts is $\ce{K2SO4}$ and I know that the anion of the second salt is $\ce{Cl-}$. I know that the second salt is either $\ce{MgCl2}$, $\ce{NaCl}$, $\ce{CaCl2}$, or $\ce{KCl}$.
I tested for the anion for the second salt by adding $\ce... |
Recently I was researching $\ce{Ca(OH)_2}$, and I found this on Wikipedia:
![enter image description here][1]
Can you explain why solubility decreases when temperature increases?
[1]: https://i.stack.imgur.com/WXF1ym.png |
You are perfectly right on that you need to convert the carboxylic acid to a more reactive species to eventually obtain the amide!
Playing with the pH will not help:
- under acidic conditions, the amine is protonated and therefore unreactive
- under alkaline conditions, the acid is deprotonated and the carb... |
${K_c}$ of reverse reaction should just be the reciprocal of forward ${K_c}$. So, ${K_c}$ of reverse reaction is $\frac{1}{1752}$.
Now, I am not sure, why you used 2nd equation. Suppose you have 1 unit conc of $\ce{NO}$ and $\ce{O_2}$, then after time $t$, if the conversion is $x$, then your equation should be
$... |
How can I compare the leaving group ability of $\ce{Br^+}$ and $\ce{Cl^+}$ ions for the electrophilic substitution reactions for aromatic compounds? |
Here is the scenario: we heat up a substrate in a solvent in a container ( say a beaker) to make it excited and then it reacts. Question: how energy is transferred?
When we heat up a molecule to make it excited actually we transfer energy to its highest occupied orbital electrons to excite them to a higher state. I... |
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