instruction stringlengths 15 21.8k |
|---|
How can I keep milk from spoiling? |
I am trying to find a way to keep milk from spoiling and/or turning yellow.
Apparently there is a process for achieving this, and I am aware that there is a lady who creates milk beads for resin jewelry and she claims that she is able to prevent the milk from spoiling/yellowing over time.
I have heard that you ca... |
How can I keep milk from spoiling and/or turning yellow? |
How much CO2 could you remove from the atmosphere if you had 2 trillion USD to spend on the problem? |
Is there any experimental evidence for OClF5? |
Which argon compounds exist, supported by experiment or computation? |
I know it's possible to capture $\ce{CO2}$ with various chemical reactions. For example NASA's space shuttle had some kind of [regenerative $\ce{CO2}$ scrubber][1]. But how expensive is it? Could a huge number of these devices, or something like it, significantly reduce the atmosphere's $\ce{CO2}$ level?
I realize t... |
> Does the secondary quantum number tell how many subshells a specific
> principal quantum number shell has?
No, it does not. It is the principal quantum number $n$ which does it (as you actually mentioned yourself later in the question). The second quantum number $l$ describes the shape of the orbitals in a partic... |
I understand that melt flow rate and density can be used to classify HDPE. Does this mean that if I have the melt flow rate and density of an HDPE (with no additives), then I can know its other material properties? |
Do melt flow rate and density tell you everything about pure HDPE? |
London Dispersion forces are forces between non-polar non-ionic molecules that the random fluctuation of their electrons makes them temporarily dipoles. What is the frequency that this occurs? Every how many miliseconds does a molecule like this becomes a dipole? (if you have a number for specific molecules would be ni... |
how often does a non polar molecule becomes dipole to exert London Dispersion forces? |
London Dispersion forces are forces between non-polar non-ionic molecules that the random fluctuation of their electrons makes them temporarily dipoles.
- What is the frequency that this occurs?
- Every how many milliseconds does a molecule like this becomes a dipole?
- Are there such numbers for some specific ... |
How often does a non polar molecule becomes dipole to exert London Dispersion forces? |
It's very difficult to get accurate information concerning the household bleach residues. Imagine for instance you pour pure (or diluted) bleach on a fabric or synthetic foam and let it dry without rinsing (as a scientific experimentation). [Some sources][1] say: it will totally "vanished" (with air and/or light), leav... |
At what frequency does a non-polar molecule acquire a dipole able to participate in London Dispersion forces? |
Of course, there are many types of coffee, so *I would like a range of lethal dose amounts for the average human, from the mildest of lattes to the most hardcore of espressos.*
**Pure caffeine's lethal dose is easily calculable, but what about coffee?** |
What is the lethal dose ( LD50 ) of coffee? |
Being an ionic solid, salt is very susceptible to being torn apart by the polar molecules of water. Inside the water, salt exists as sodium and chlorine anions; **but what state of matter is it in?**<br> My instinct tells me it is in a solid state, as salt's melting point is *800°C*, but it sure doesn't really act like... |
What phase of matter is salt when dissolved in water? |
The quaters in which I live has both Aluminium and Copper wires for household wiring. This results in corrosion of the contacts and hence leads to miscontact, sparking, overheating and even fire.
Is there any way to inhibit the corrosion(if not stop completely), except for changing the whole wiring ?
|
The quarters in which I live has both aluminum and copper household wiring. This results in corrosion of the contacts and can lead to sparking, overheating, and even fire.
Is there any way to inhibit the corrosion (if not stopping it completely), except for changing the whole wiring?
|
*Salt* is a famous regularly repeating cubic crystal, but there are always natural deformities and flaws present. I have heard that graphene is an extremely uniform substance. **With these in mind,**<br> **what is the most regular crystal pattern, natural or man-made?** |
What bond\crystal has the most regular pattern (i.e. least irregularities)? |
Being an ionic solid, salt is very susceptible to being torn apart by the polar molecules of water. Inside the water, salt exists as sodium and chlorine anions; **but what state of matter is it in?**<br> My instinct tells me it is in a solid state, as salt's melting point is *800°C*, but it sure doesn't really act like... |
I'd like to reduce enantioselectively a ketone in presence of an ester (which should NOT be reduced to an aldehyde and further to an alcohol).
- In the following reaction ([Frater-Seebach Alkylation][2]) they used Bakers yeast:
[![enter image description here][1]][1]
- Probably S-BINAP also give **2**.
... |
How can a ketone selectively be reduced? (Frater Seebach Alkylation) |
I'd like to reduce enantioselectively a ketone in presence of an ester (which should NOT be reduced to an aldehyde and further to an alcohol).
- Adding $\ce{LIAlH4}$ would also reduce the ester and gives no enantioselective reduction of the ketone.
- In the following reaction ([Frater-Seebach Alkylation][2]) th... |
I'd like to reduce enantioselectively a ketone in presence of an ester (which should NOT be reduced to an aldehyde and further to an alcohol).
- Adding $\ce{LIAlH4}$ would also reduce the ester and gives no enantioselective reduction of the ketone.
- In the following reaction ([Frater-Seebach Alkylation][2]) th... |
I'd like to reduce enantioselectively a ketone in presence of an ester (which should NOT be reduced to an aldehyde and further to an alcohol).
- Adding $\ce{LIAlH4}$ would also reduce the ester and gives no enantioselective reduction of the ketone.
- In the following reaction ([Frater-Seebach Alkylation][2]) th... |
I'd like to deprotect a benzyl group for a Frater Seebach alkylation (see also: http://chemistry.stackexchange.com/questions/34519/how-can-a-ketone-selectively-be-reduced-frater-seebach-alkylation).
[![enter image description here][1]][1]
Will the first reaction with $\ce{Li/NH3}$ work or will the ester ketone ge... |
How to deprotect a benzyl ether? |
I'd like to reduce enantioselectively a ketone in presence of an ester (which should NOT be reduced to an aldehyde and further to an alcohol).
- Adding $\ce{LiAlH4}$ would also reduce the ester and gives no enantioselective reduction of the ketone.
- In the following reaction ([Frater-Seebach Alkylation][2]) th... |
Why is this reaction successful:
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/5i9V1.gif
Why doesn't metal-halide exchange occur easily to get Ar-MgCl and R-Br? |
The modified Arrhenius equation is used to express the rate constant in a chemical mechanism model I'm working with. The equations is as follows:
$$k_\mathrm{f} = A\times T^b\times\exp\left(-\frac{E_\mathrm{a}}{RT}\right)$$
The paper states that "Units are Moles, cm3, Seconds, K, and Calories/Mole" so what would be t... |
I'd like to deprotect a benzyl group for a Frater Seebach alkylation (see also: http://chemistry.stackexchange.com/questions/34519/how-can-a-ketone-selectively-be-reduced-frater-seebach-alkylation).
[![enter image description here][1]][1]
Will the first reaction with $\ce{Li/NH3}$ work or **will the ester ketone ... |
How to deprotect a benzyl ether? (Birch reduction) |
The claim that "the tars in cannabis are considerably more dangerous than those in tobacco" is made in Patricks An Introduction to Medicinal Chemistry (4th edition, p. 169). It's just a simple one line statement and not much attention is given to it, but from what I already knew this is to say the least a very controve... |
Are the tars in cannabis considerably more dangerous than those in tobacco? |
I recently saw a video on making liquid CO2:
https://www.youtube.com/watch?v=8AN_XMcD3yI
Basically we seal some dry ice in a container. As the dry ice sublimates the pressure inside the container increases and so at about 5 atm we reach the triple point of CO2, at which point the solid CO2 melts instead of sublimat... |
I think [these][1] [three][2] [links][3] nicely summarize what can potentially go wrong when a plastic bottle explodes.
As for your question about how much pressure the Gatorade container can hold, that's a little trickier to figure out. It looks like the [Mythbusters found that soda bottles can hold up to 150psi (~... |
My textbook said Le Chatelier's principle applies normally to gases but there is no explanation. I did some googling and it said if you increase the pressure, it will shift to the side with less moles of gas. What does this really mean? |
How does Le Chatelier's principle work in a gaseous system? |
Please go through papers by Prof. Ralf Ludwig. You will certainly gain a lucid understanding of the subject both at experimental end as well as computational end. He advocates use of low frequency vibrational modes such as Far IR along with quantum chemistry for studying hydrogen bonding and allied weak interactions in... |
I have been synthesizing TCPO (for chemiluminescent reaction) using 2,4,6 trichlorophenol and oxalyl chloride.
Since I am tired of paying for oxalyl chloride (and hazard class 3 shipping), I wish to find a synthetic route to produce my own stock.
The most common synthesis of oxalyl chloride uses oxalic acid and p... |
I know how kucerov reaction works for aliphatic alkines, but what if the alkine has a phenyl attached? How will the aromatic ring affect the reaction of alkines with water? |
How works the Kucerov reaction if the alkine is aromatic? |
Periodic acids cleave 1,2 diols by forming an periodate ester as an intermediate. Osmium tetroxide also forms an osmate ester with alkenes and yields syn diols after a hydrolysis step. Given that their structures are so similar, why doesn't periodic acid also succeed in forming diols with alkenes? (These in another ste... |
I recently saw a video on making liquid $\ce{CO2}$:
https://www.youtube.com/watch?v=8AN_XMcD3yI
Basically we seal some dry ice in a container. As the dry ice sublimates the pressure inside the container increases and so at about 5 atm we reach the triple point of $\ce{CO2}$, at which point the solid $\ce{CO2}$ melt... |
I know how Kucherov reaction work for aliphatic alkynes, but what if the alkyne has a phenyl attached? How will the aromatic ring affect the reaction of alkynes with water? |
How does the Kucerov reaction work if the alkyne is aromatic? |
I know how the Kucherov reaction works for aliphatic alkynes, but what if the alkyne has a phenyl attached? How will the aromatic ring affect the reaction of alkynes with water? |
How does the Kucherov reaction work if the alkyne is aromatic? |
I'd like to deprotect a benzyl group for a Frater Seebach alkylation (see also: http://chemistry.stackexchange.com/questions/34519/how-can-a-ketone-selectively-be-reduced-frater-seebach-alkylation).
[![enter image description here][1]][1]
Will the first reaction with $\ce{Li/NH3}$ work or **will the ester ketone ... |
Our lab uses a sodium hydroxide solution of a (theoretically) known normality (0.8000 - 1.0000) to titrate product samples for quality control. However, we suspect that the normality of the NaOh left in the burette / tubing connected to our container is changing if we let it sit (our tests come out wrong, and the answ... |
Our lab uses a sodium hydroxide solution of a (theoretically) known normality (0.8000 - 1.0000) to titrate product samples for quality control. However, we suspect that the normality of the $\ce{NaOH}$ left in the burette / tubing connected to our container is changing if we let it sit (our tests come out wrong, and t... |
I have a large amount of copper sulfate available and I am interested in obtaining copper chloride from it. What is the easiest way to do so?
I have considered mixing an aqueous solution of copper sulfate with sodium chloride, but I think that it would be difficult to separate the resulting sodium sulfate from the c... |
Why don't periodic acids cleave 1,2 diols to ketones? |
I have a large amount of copper sulfate available and I am interested in obtaining copper chloride from it. What is the easiest way to do so?
I have considered mixing an aqueous solution of copper sulfate with sodium chloride, but I think that it would be difficult to separate the resulting sodium sulfate from the c... |
The periodic table has 7 periods and they have 2,8,8,18,18... elements respectively from 1 to 7. But from what I understand, the periods each state the number of electron shells that the elements in that period has. So if that is the case, shouldn't period 3 have more elements, since it can hold up to 18 electrons, and... |
It is said that covalent bonds are directional, while ionic are not. Why ? Is it something because of the orientation/ directional properties of the overlaping orbitals ? |
Why are covalent bonds directional? |
It is said that covalent bonds are directional, while ionic bonds are not. Why? Is it because of the orientation/directional properties of the overlapping orbitals? |
> So if that is the case, shouldn't period 3 have more elements, since
> it can hold up to 18 electrons, and therefore it can have up to 18
> more protons from the largest atomic number element in period 2?
Indeed, elements of the same period have the same number of electron shells, but the "problem" is that in ac... |
> So if that is the case, shouldn't period 3 have more elements, since
> it can hold up to 18 electrons, and therefore it can have up to 18
> more protons from the largest atomic number element in period 2?
Indeed, elements of the same period have the same number of electron shells, but the "problem" is that in ac... |
> So if that is the case, shouldn't period 3 have more elements, since
> it can hold up to 18 electrons, and therefore it can have up to 18
> more protons from the largest atomic number element in period 2?
Indeed, elements of the same period have the same number of electron shells, but the "problem" is that in ac... |
I am a high school student and I was reading a textbook and it gave me the equation of this hydrochloric acid which was put into water and the products formed were Hydronium and chlorine.
$HCL + H_20 \longrightarrow H_30^+ + Cl^-$
I understand that HCL (Hydrochloric acid) breaks up in the water to become 2 free... |
Why in $HCL + H_20 \longrightarrow H_30^+ + Cl^-$ is Chlorine free? |
I am a high school student and I was reading a textbook and it gave me the equation of this hydrochloric acid which was put into water and the products formed were Hydronium and chlorine.
$\ce{HCl + H_2O -> H3O^+ + Cl^-}$
I understand that $\ce{HCl}$ (Hydrochloric acid) breaks up in the water to become 2 free i... |
Why in HCl + H2O -> H3O+ + Cl- is Chlorine free? |
I am a high school student and I was reading a textbook and it gave me the equation of this hydrochloric acid which was put into water and the products formed were hydronium and chlorine.
$\ce{HCl + H2O -> H3O+ + Cl-}$
I understand that $\ce{HCl}$ (Hydrochloric acid) breaks up in the water to become 2 free ions... |
Why do chloride ions not bond to water molecules/hydronium ions when hydrochloric acid dissociates? |
$S^{2-}$, $Cl^-$, $K^+$, and $Ca^2+$ each have the same number of electrons. Their atomic radius is 182. 181, 138, and 100 picometers respectively, and their respective number of protons is 16,17,18, and 19. My question is, why does the atomic radius drastically go from 181 to 138 picometers between Chlorine and Potass... |
Why are there drastic changes sometimes in radius of isoelectronic ions? |
$\ce{S^{2-}}$, $\ce{Cl-}$, $\ce{K+}$, and $\ce{Ca^{2+}}$ each have the same number of electrons. Their atomic radius is 182. 181, 138, and 100 picometers respectively, and their respective number of protons is 16,17,18, and 19. My question is, why does the atomic radius drastically go from 181 to 138 picometers between... |
$\ce{S^{2-}}$, $\ce{Cl-}$, $\ce{K+}$, and $\ce{Ca^{2+}}$ each have the same number of electrons. Their effective ionic radii are 182, 181, 138, and 100 picometers, respectively, and the number of protons for each are 16, 17, 18, and 19. My question is, why does the effective ionic radius drastically go from 181 to 138 ... |
Our lab uses a sodium hydroxide solution of a (theoretically) known normality (0.8000 - 1.0000) to titrate product samples for quality control. However, we suspect that the normality of the $\ce{NaOH}$ left in the burette/tubing connected to our container is changing if we let it sit (our tests come out wrong, and the... |
Is there an adhesive with an On-and-Off Switch? |
Is there an adhesive with an on-and-off switch? |
I'm working through problems in my textbook. How much heat is required to convert 2.55 g of $H_{2}O$ at $28^{\circ}$C to steam at $100^{\circ}$?
In simpler problems I've used the fact that $\Delta H_{fus}$ = 6.02 kJ/mol for $H_{2}O$ at a melting point of $0^{\circ}$ to do these kinds of calculations. But here the te... |
I'm working through problems in my textbook. How much heat is required to convert 2.55 g of $\ce{H2O}$ at 28°C to steam at 100°C?
In simpler problems I've used the fact that $\Delta H_{fus}$ = 6.02 kJ/mol for $\ce{H2O}$ at a melting point of 0°C to do these kinds of calculations. But here the temperatures are differ... |
How to define a new solvent in Gaussian09 to run SCRF? |
1. [Pubchem compound 6140](https://pubchem.ncbi.nlm.nih.gov/compound/L-phenylalanine) is L-phenylalanine in its neutral (not zwitterionic) form. According this PubChem, this molecule has the following SMILES and InChI indentifiers:
- Smiles: C1=CC=C(C=C1)CC(C(=O)O)N
- Inchi: InChI=1S/C9H11NO2/c10-8(9(11)12)6-7-4-2... |
I am currently working on an investigation where I am burning isomers of butanol to test for the heat of combustion values to see which fuel is most efficient. The fuels I am testing are 1-butanol, 2-butanol, 2-methylpropan-1-ol (isobutanol) and 2-methylpopan-2-ol (tert-butyl alcohol).
I have researched that the hea... |
What causes the difference in heat energy released by combustion for the Butanol isomers? |
Most of the common organic solvents are regarded as noncorrosive, but stainless steel can be attacked by formic, acetic, and propanoic acids.
[Corrosion of stainless steel by organic solvent mixtures, Alice Y. Ku , David H. Freeman, Anal. Chem., 1977, 49 (11), pp 1637–1638
DOI: 10.1021/ac50019a044][1]
I wonder... |
$$\ce{NH_3 + HCl -> NH_4Cl}$$
The ammonia is bonded so that the nitrogen has an outer shell with a lone pair of electrons.
When they react, the hydrogen from the $\ce{HCl}$ moves to the ammonia, however it leaves its electrons behind because there is already a lone pair of 2 electrons on the $\ce{N}$ atom which ... |
I am currently working on an investigation where I am burning isomers of butanol to test for the heat of combustion values to see which fuel is most efficient. The fuels I am testing are 1-butanol, 2-butanol, 2-methylpropan-1-ol (isobutanol) and 2-methylpopan-2-ol (tert-butyl alcohol).
I have researched that the hea... |
I'm working through problems in my textbook. How much heat is required to convert 2.55 g of $\ce{H2O}$ at 28 °C to steam at 100 °C?
In simpler problems I've used the fact that $\Delta H_\text{fus} = 6.02\ \mathrm{kJ/mol}$ for $\ce{H2O}$ at a melting point of 0 °C to do these kinds of calculations. But here the tempe... |
I understand that there is a pressure gradient between an aqueous solution, e.g. salty water, and, say, pure water due to osmosis. My question is, is it possible to match or almost match, the osmotic pressure between two solutions of different solutes, but using a solution with a different solute. For example, would it... |
Can I equalise osmotic pressure using two different solutes? |
$\ce{S^{2-}}$, $\ce{Cl-}$, $\ce{K+}$, and $\ce{Ca^{2+}}$ each have the same number of electrons. Their effective ionic radii are 182, 181, 138, and 100 picometers, respectively, and the number of protons for each are 16, 17, 19, and 20. My question is, why does the effective ionic radius drastically go from 181 to 138 ... |
How can we know whether a compound has a coordinate bond or not?
Yes,I know that I have to draw the Lewis Structure for the compound .But what to do after that? Is there anything to do with formal charges? |
How can we know whether a compound has a coordinate bond or not? I know that I have to draw the Lewis Structure for the compound. But what to do after that? Is there anything to do with formal charges? |
These dishwasher tablets ([Finish Powerball Shine](http://www.finish.co.uk/shine-and-protect/)) seem to be covered in plastic!
[![Film-covered dishwasher tablets][1]][1]
But that can't possibly be true since there's no unwrapping, and they're completely soluble in water.
What is the film made of?
[1]: ... |
What is the transparent film that covers water-soluble dishwasher tablets? |
The modified Arrhenius equation is used to express the rate constant in a chemical mechanism model I'm working with. The equations is as follows:
$$k_\mathrm{f} = A\times T^b\times\exp\left(-\frac{E_\mathrm{a}}{RT}\right)$$
The paper states that "Units are Moles, cm3, Seconds, K, and Calories/Mole" so what would be t... |
I first tried to find the equation like this:
$$k=\frac{2.303}{t}log\frac{a}{a-x}$$
Let k/2.303 be c. Here, 'a' is the initial concentration of reactant.
$$\frac{a}{a-x}=10^{ct}$$
$$x=a(1-10^{-ct})$$
$$\frac{dx}{dt}=a(c.ln10.10^{-ct})=ak10^{\frac{kt}{2.303}}$$
Now dx/dt is $\sqrt{3}$. But the value of initial co... |
I'm asking this because I found a <a href="link.htmlhttp://www.sigmaaldrich.com/life-science/core-bioreagents/biological-buffers/learning-center/buffer-reference-center.html">link</a> for imidazole-HCl buffer: , but from what I understand, a buffer is a weak acid or base with its corresponding salt. Would imidazole-HCl... |
Does imidazole and hydrochloric acid yield imidazole hydrochloride salt? |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.