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Estimating maximum size of magnetite particles in this Nile Red ferrofluid video? |
Iodine povidone is a complex of iodine and the polymer povidone. I am wondering if one were to heat it enough, the iodine would sublimate and could be collected. Normally iodine boils at 184.3 °C, according to wikipedia.
A video of how the procedure might work, except iodine crystals would replaced with boiled down... |
Recently the YouTube chemist Nile Red performed an interesting conversion from aspirin to paracetamol [Aspirin to Acetaminophen - Part 1 of 6: Extracting Aspirin from Pills](https://www.youtube.com/watch?v=YPIr26-Tg5c) using the following steps:
[![enter image description here][1]][1]
He performed the following... |
> How can an Organic chemist know the *chemical formula* of a natural product she isolated from an organism?
There are two levels of answers. One is historical and one is modern.
Historically, determining the chemical formula for had been a trivial job for most small or medium sized molecules. You do a combustion... |
I already asked this on Worldbuilding Stack, but they told me to ask here. It is for a RPG campaign.
Are there any options that an evil person could use to keep someone awake against their will? Like a gas, an injection, or any substance or simple practice that wouldn't allow them to sleep even if they wanted to?
... |
Options to keep someone awake against their will? |
> Working on-board a research vessel somewhere at sea, you have (carefully) isolated 12.5 micrograms $(\pu{12.5E-6 g})$ of what you hope is pure saxitoxin (a non-electrolyte) from a poisonous (and quite cross) puffer fish. You dissolve this sample in $\pu{3.10 mL}$ of water and determine that the osmotic pressure of
t... |
I learnt from my textbook and the question/answer - *https://chemistry.stackexchange.com/q/19001/81509* that active mass of a solid or liquid is taken to be unity as:
$$[A]=\frac n V=\frac{m}{M\times V}=\frac{\rho}{M}=k$$
where $[A]$ is the active mass, $n$ is the amount of substance, $V$ is the volume, $m$ is th... |
What is Rinman's green used for? |
Terylene is a polyester made from terephthallic acid and ethylene glycol.Even though we use two reagents,they undergo esterification to give Bis(2-Hydroxyethyl)terephthalate(monomer) which then undergo polymerization.So is it correct to consider terylene as a copolymer.My reasoning tells that it should be a homopolymer... |
Is terylene a copolymer? |
I am trying to detect tylosin tartrate from the mixture of doxycycline hyclate using $\pu{0.01 M}$ $\ce{HCl}$ as solvent, and waveleghth of $\pu{290 nm}$ for detecting tylosin tartrate in UV-spectrophotometer but the method fails
The aim is finding an analytical UV-spectro photometer method to detect tylosin tart... |
While testing for formaldehyde (an aldehyde), I added Fehling's solution to the sample and let the test tube simmer in a water bath for some time. I returned ~15 minutes later to see a black/dark grey precipitate awaiting me, which looked very metallic (Almost like Tollen's test, but darker)
I try again and this tim... |
Fehling's solution turning yellow and then black? |
> How can an Organic chemist know the *chemical formula* of a natural product she isolated from an organism?
There are two levels of answers. One is historical and one is modern. Historically, determining the chemical formula for had been a trivial job for most small or medium sized molecules. You do a combustion an... |
> Is the spectrum due to the high voltage depends on the atomic properties of the metal?
Yes, the atomic emission spectrum is unique for each element. The electrical voltage plays a secondary role in my opinion, it is rather the temperature which determines which line would be visible in the emission spectrum. These... |
As a non chemist I am always charmed when visiting Wikipedia articles of chemical elements and see images of very pure deposits of element after element, proton by proton and often also metal cube made from smithing similar pure deposits.
The wiki article [Periodic table][1] allows me to do so easily; here are some ... |
As the title implies, what caused the association between $H^{+}$ and acidity, and between $OH^{-}$ and basicity? |
Why is H⁺ ion considered the source of acidity, and $OH^{-}$ considered the source of basicity? |
As a non chemist I am most often charmed when visiting Wikipedia articles of chemical elements and see images of very pure deposits of element after element, proton by proton and often also metal cube made from smithing similar pure deposits.
The wiki article [Periodic table][1] allows me to do so easily; here are s... |
> A 2.35 mole sample of an ideal gas, for which $C_{\mathrm{m},v}=3R/2$ initially at $\pu{27 ^\circ C}$ and $\pu{1750 kPa}$, undergoes a two stage transformation. For each of the stages described in the following list, calculate the final pressure as well as $q$, $w$, $\Delta U$ and $\Delta H$. Also calculate $q$, $w$,... |
How to calculate the pressure of an ideal gas that undergoes isothermal expansion? |
I desire to learn whether levomenthol is superior to Menthol as a pain killer in humans.
I didn't find a wiki article about levomenthol and the article [Menthol][1] doesn't mention this molecule.
The chemical formulas are the same but I understand that the only difference is the spatial position of chemical bonds... |
Is levomenthol superior to Menthol as a pain killer in humans and what are the ways to determine this? |
As a non chemist I am most often charmed when visiting Wikipedia articles of chemical elements and see images of very pure specimens of element after element, proton by proton, and often also metal cube specimen made from smithing similar pure deposits.
The wiki article [Periodic table][1] allows me to do so easily;... |
How can chemists distinguish pure chemical element specimens that look almost "the same" as well as what deposit is what in a multimineral mined rock? |
Consider this simple two step reaction, a variant of a Michaelis-Menten type of problem, where $\ce{A}$ and $\ce{B}$ reversibly bind to make $\ce{AB}$, and $\ce{AB}$ and $\ce{C}$ reversibly bind to make $\ce{ABC}$:
\begin{align}
\ce{A + B &<=> AB}\\
\ce{AB + C &<=> ABC}
\end{align}
Assume all the rate constan... |
How to derive the steady-state solution for simple two-step reaction with differential equations? |
As a non chemist I am most often charmed when visiting Wikipedia articles of chemical elements and see images of very pure specimens of element after element, proton by proton, and often also metal cube specimen made from smithing similar pure deposits.
The wiki article [Periodic table][1] allows me to do so easily;... |
Yours is a historical question. Note that in modern chemistry, it is not required that acids have H+ or bases have OH-. Definitions are made by humans and I am glad you are not blindly accepting the definitions and at least thinking about them. Arrhenius was among the first ones to think why solutions conduct electrici... |
Yours is a historical question. Note that in modern chemistry, it is not required that acids have H+ or bases have OH-. The words acidity or basicity referred to certain common behaviors such as acids will liberate hydrogen when come in contact with metals, or they will decompose carbonates to carbon dioxide. Similarly... |
I want to understand the assumptions that have to be fulfilled in order for the steady state approximation to work. I did some research myself and was able to deduce assumptions of the form $k_1\gg k_2$ for some systems, by solving the system exactly and taking the limiting case in which the exact system reduces to the... |
Per a 2017 article from the [Journal of Molecular Liquids](https://www.sciencedirect.com/science/article/abs/pii/S0167732216317664) some interesting comments.
Yes, you can use HCl albeit in conjunction with a chlorate (or bromate or iodate..) and added chloride, to quote:
>It has been found that mixtures between... |
Per a 2017 article from the [Journal of Molecular Liquids](https://www.sciencedirect.com/science/article/abs/pii/S0167732216317664) some interesting comments.
Yes, you can use HCl albeit in conjunction with a chlorate (or bromate or iodate..) and added chloride, to quote:
>It has been found that mixtures between... |
So, okay. I study chemistry in an University and I have two professors that says opposing things. One says that the physical state must be subscribed (1 at the picture) and other that it must be written to the left side (2). Since both of them are posdocs and have way more experience in chemistry than me, I really don'... |
The below image (source: [here][1]) is from a fractional distillation of a mixture of two liquids, one with a boiling point of 69 degrees celsius and the other with a boiling point of 98 degrees celsius. In this diagram, it appears that the first drop of distillate occurs at the boiling point of the component with the ... |
When exactly does the first drop of distillate appear in a distillation? |
>Write an equation for the reaction you might expect to take place if trichloroethanoic acid, $\ce{Cl3CCO2H}$, $\mathrm{p}K_\mathrm{a} = 0.65$, were added to dimethylpropanoic acid, $\ce{(CH3)3CCO2H}$, $\mathrm{p}K_\mathrm{a} = 5.05$. Explain your answer in terms of the Brønsted–Lowry theory.
I know that $\ce{Cl3CCO... |
I would like to think of the following equation:
aA (g) + bB (g) -> cC(g) where a+ b < c and A,B C are different gases.
Is there such chemical reaction? |
Is there any kind of reaction with two types of reactants (gases) and one product (also gas) such that the total volume after the reaction increases? |
Overall science is not affected by whether you write subscript or a superscript or in line. Afterall all notation was invented by humans. When professor quibble over these things my suggestion for them is to read the problem of "*How many angels can stand on the point of a pin*?" Apparently when Constantinople was fall... |
> **TL;DR**
> Contrary to what the answers/comments have suggested, I would say that ***no reaction*** happens here. The acid–base reaction between the two given species is thermodynamically unfeasible, with an equilibrium constant $K \sim 10^{-9}$.
----------
If you want an acid-base reaction to occur between... |
I study chemistry in an University and I have two professors that says opposing things. One says that the physical state must be subscribed (1 at the picture) and other that it must be written to the left side (2). Since both of them are posdocs and have way more experience in chemistry than me, I really don't know to ... |
Overall science is not affected by whether you write subscript or a superscript or in line. Afterall all notation was invented by humans. When professor quibble over these things my suggestion for them is to read the problem of "*How many angels can stand on the point of a pin*?" Apparently when Constantinople was fall... |
As the title implies, what caused the association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and basicity? |
Why is H⁺ ion considered the source of acidity, and OH⁻ considered the source of basicity? |
Terylene is a polyester made from terephthallic acid and ethylene glycol. Even though we use two reagents, they undergo esterification to give bis(2-hydroxyethyl) terephthalate (monomer) which then undergo polymerization.
So, is it correct to consider terylene as a copolymer? My reasoning tells that it should be a h... |
I would like to think of the following equation:
$$\ce{aA(g) + bB(g) -> cC(g)}$$
where $a + b < c$ and $\ce{A},$ $\ce{B}$ and $\ce{C}$ are different gases.
Is there such chemical reaction? |
why is the HOMO-LUMO gap in N2 and CO different even though they have the same number of valence electrons? |
Inorganic Lab Report Help! Why is the HOMO-LUMO gap in N2 and CO a different size? |
Given a set of atoms and their positions in space, is there a way to compute the bond spring constant for each pair of atoms that are considered to be bonded (I can already determine the bonds with OpenBabel)? I don't want to rely on empirical data, and it's okay if the spring constant is wrong by up to about 20%. I al... |
My highschool textbook tells me that sacrificial protection (cathodic protection is its more technical name) and electrolytic protection are different. I have searched high and low for an explanation of electrolytic protection, but nothing.
It describes the electrolytic protection, stating that the steel/iron struct... |
What on earth is electrolytic protection? |
Why is the HOMO-LUMO gap in $\ce{N2}$ and $\ce{CO}$ different even though they have the same number of valence electrons? |
Why is the HOMO-LUMO gap in N2 and CO of different sizes? |
**Aqueous solutions**
In aqueous solution, $\ce{H+(aq)}$ and $\ce{OH-(aq)}$ are always present because of the autoionization of water:
$$\ce{H2O(l) <=> H+(aq) + OH-(aq)}$$
So in aqueous solution, I would be comfortable saying there is an "association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and ba... |
**Aqueous solutions**
In aqueous solution, $\ce{H+(aq)}$ and $\ce{OH-(aq)}$ are always present because of the autoionization of water:
$$\ce{H2O(l) <=> H+(aq) + OH-(aq)}$$
So in aqueous solution, I would be comfortable saying there is an "association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and ba... |
**Aqueous solutions**
In aqueous solution, $\ce{H+(aq)}$ and $\ce{OH-(aq)}$ are always present because of the autoionization of water:
$$\ce{H2O(l) <=> H+(aq) + OH-(aq)}$$
So in aqueous solution, I would be comfortable saying there is an "association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and ba... |
In class, we discussed the following multiple-choice question.
> The rate expression for a reaction is:
> $$rate = k[X][Y]$$
> Which statement is correct?
> **A.** As the temperature increases, the rate constant decreases.
> **B.** The rate constant increases with increased temperature, but eventually reach... |
In order to determine the relative contributions of resonance structures, my textbook gives the following rules (in order):
1. The more covalent bonds a structure has, the higher it scores.
2. Structures in which all of the atoms have a complete valence shell of electrons (i.e., the noble gas structure) are esp... |
How to determine the relative contribution of resonance structures when different rules give contradictory outcomes? |
So I was "happily" doing organic chemistry homework when I came across this question:
> For 1-methoxy-1,3-butadiene, which of the following resonating structure is the least stable?
> $$\begin{align}(\mathbf{a})\ &\ \ce{H2\overset{+}{C}-\overset{+}{C}H-CH=CH-O-CH3} & (\mathbf{b})\ &\ \ce{H2\overset{+}{C}-CH=CH-CH... |
How to determine the worst resonance structures out of a given set? |
Larmor precession is the phenomenon that in NMR the spin (and by default also the magnetic dipole moment) of protons does not line up with the applied magnetic field but rather precesses around this direction at a certain angle.
[![Larmor precession][1]][1]
The concept of Larmor precession confuses me for several... |
Why does Larmor precession occur in NMR? |
>***Which of the contributing structures of the resonance is more stable?***
>![enter image description here][1]
I'm watching a video lecture by a professor of my college where he puts this question to the class. The class unanimously says **B**. At first I thought they were wrong, but then the professor agreed w... |
Oxygen or carbon with a positive charge? (comparison of canonical structures) |
In class, we discussed the following multiple-choice question.
> The rate expression for a reaction is:
> $$rate = k[X][Y]$$
> Which statement is correct?
> **A.** As the temperature increases, the rate constant decreases.
> **B.** The rate constant increases with increased temperature, but eventually reach... |
How does the rate constant change with the change of the temperature? |
> Working on-board a research vessel somewhere at sea, you have (carefully) isolated 12.5 micrograms $(\pu{12.5E-6 g})$ of what you hope is pure saxitoxin (a non-electrolyte) from a poisonous (and quite cross) puffer fish. You dissolve this sample in $\pu{3.10 mL}$ of water and determine that the osmotic pressure of
t... |
I have been trying to find a chemical reaction for the formation of acetic acid from glycerol. I have been searching different literature, but apparently the reaction can not be found. I was hoping maybe anyone here would know the reaction.
$$C_3H_8O_3 + X = C_2H_4O_2 + X$$
**Some Background**
I am working on ... |
My highschool textbook tells me that sacrificial protection (more technically-cathodic protection) and electrolytic protection are different. I have searched high and low for an explanation of electrolytic protection, but I got nothing.
It describes the electrolytic protection, stating that the steel/iron structure ... |
What is electrolytic protection? |
**Aqueous solutions**
In aqueous solution, $\ce{H+(aq)}$ and $\ce{OH-(aq)}$ are always present because of the autoionization of water:
$$\ce{H2O(l) <=> H+(aq) + OH-(aq)}$$
So in aqueous solution, I would be comfortable saying there is an "association between $\ce{H+}$ and acidity, and between $\ce{OH-}$ and ba... |
I have been trying to find a chemical reaction for the formation of acetic acid from glycerol. I have been searching different literature, but apparently the reaction can not be found. I was hoping maybe anyone here would know the reaction.
$$C_3H_8O_3 + X = C_2H_4O_2 + X$$
**Some Background**
I am working on ... |
The fundamental equation of thermodynamics states that $dG = VdP-SdT$. I am having difficulty understanding this equation. The Wikipedia page for Gibbs free energy says:
> ... is a thermodynamic potential that can be used to calculate the maximum of reversible work that may be performed by a thermodynamic system at... |
If I calibrate my conductivity probe using KCL calibration solution, then test my aquarium water which is NaCL, will I get a false reading? When I use a digital refractometer calibrated to zero using distilled water and test my saltwater aquarium, it reads 35 PPT but when I use a conductivity probe calibrated using KCL... |
I read that concave points in a Frost diagram disproportionate. But what are the products of the disproportionation?
For example, in the Frost diagram for manganese at pH = 0, the species $\ce{HMnO4-}$ is concave with respect to $\ce{MnO4-}$ and $\ce{H3MnO4}$. But at the same time, it is also concave with respect to... |
How to predict disproportionation products from Frost diagram? |
I wish to calculate the energy for a protein where the position of all the C-alpha atoms is known.
One way is to calculate the pairwise distances between the atoms and then look up a probability distribution to determine the likelihood that the distance for that particular pair is the given value, take the negative... |
I wish to calculate the energy for a protein where the position of all the C-alpha atoms is known.
One way is to calculate the pairwise distances between the atoms and then look up a probability distribution to determine the likelihood that the distance for that particular pair is the given value, take the negative... |
If I calibrate my conductivity probe using KCl calibration solution, then test my aquarium water which is NaCl, will I get a false reading? When I use a digital refractometer calibrated to zero using distilled water and test my saltwater aquarium, it reads 35 PPT but when I use a conductivity probe calibrated using KCl... |
Liquid neon freezer? |
The equation for Gibbs Free Energy demonstrates how the standard change in Gibbs Free Energy for a reaction is affected by temperature.
[![Equation][1]][1]
[1]: https://i.stack.imgur.com/hyX4I.png
However, to my understanding, the equation makes the inherent assumption that the standard change and enthalpy... |
The [Arrhenius equation][1] states that:
$k=A e^{\frac{-E_{a}}{R T}}$
[1]: https://en.wikipedia.org/wiki/Arrhenius_equation
What is the mathematical proof for this equation? |
The equation for Gibbs Free Energy demonstrates how the standard change in Gibbs Free Energy for a reaction is affected by temperature.
$\Delta G^o = \Delta H^o - T \Delta S^o$
However, to my understanding, the equation makes the inherent assumption that the standard change and enthalpy and the change in entr... |
#Someone *has* done what the child suggested. Sorta.#
##First, some background.##
What you're talking about is called transmutation, and for thousands of years it drove nearly all of humanity's research in chemistry (which was called alchemy at the time).
The alchemists' dream of turning "base metals" like lea... |
The equation for Gibbs Free Energy demonstrates how the standard change in Gibbs Free Energy for a reaction is affected by temperature.
$$\Delta G^\circ = \Delta H^\circ - T\,\Delta S^\circ$$
However, to my understanding, the equation makes the inherent assumption that the standard change and enthalpy and the ... |
[![enter image description here][1]][1]
For example if you look at this compound, only the benzylic carbon on the top has benzylic hydrogen, so how do we oxidize only the top part without touching the lower one (not sure if this product is right), and what happens to the CH2 in the middle?
Also, does benzylic o... |
What are the products of benzylic oxidation of cyclic compounds? |
It is well-known that the "chair" conformation of cyclohexane is the most stable of it's conformers. But is there any cyclohexane derivative where the other notable conformers (boat, half-chair) are the most stable? |
Boat Conformer of Cyclohexane Stable? |
#Preamble
One important thing to know is that what we call "resonance structure" is a byproduct of our chemical notation which can't describe the structure of some compounds effectively using only one chemical structure. Personally I find the old term **mesomeric structure** more appropriate (*meso-* Greek mésos in th... |
The atomic size aluminium to gallium is decreasing because of poor shielding eff. Of (n-1)d electrons but copper to zinc size is increasing because of the same shielding effect why ?
|
The atomic size on going from aluminum to gallium decreases because of poor shielding effect of the $(n-1)d$ electrons, but on going from copper to zinc, the size increases due to the same shielding effect. Why ?
|
It is well-known that the "chair" conformation of cyclohexane is the most stable of it's conformers. But is there any cyclohexane derivative where the other notable conformers (boat, half-chair) are the most stable?
My own intuition is that if there are 4 very bulky groups in the 1, 2, 4, 5 positions then the boat c... |
Sorry for that obvious question.
The question is in the title.
So could you please answer the question :
If i disolve 0.1M of CaCl.2H2O in Water, do i get a 0.1M CaCl2 solution ? |
If i make 0.1M of CaCl.2H2O in Water, do i get a 0.1M CaCl2 solution? |
If i make 0.1M of CaCl2.2H2O in Water, do i get a 0.1M CaCl2 solution? |
Sorry for that obvious question.
The question is in the title.
So could you please answer the question :
If i disolve 0.1M of CaCl2.2H2O in Water, do i get a 0.1M CaCl2 solution ? |
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