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 1 
 on: Today at 11:03:02 AM 
Started by sandiegofan328 - Last post by Borek
You have still not given us enough information, I have no idea what you are asked to do.

 2 
 on: Today at 09:31:21 AM 
Started by AdiDex - Last post by Borek
Then volume element around the nucleus will also increase.

Please elaborate, sounds to me like you are juggling meaningless words here.

 3 
 on: Today at 07:28:45 AM 
Started by CBPQT - Last post by pgk
As you have already mentioned, the formation of a carbocation is slow and it is the rate determinative step of the reaction; in contrast the hydrogen shift, which is very fast. Consequently, isomerization will be predominant under both thermodynamic and kinetic conditions, when using acidic catalysts (e.g. organometallic ones that are Lewis acids). But this doesn’t happen under basic conditions (e.g. SN2 nucleophilic substitution of the secondary bromide) that practically no isomerization occurs. 

 4 
 on: Today at 06:52:30 AM 
Started by AdiDex - Last post by AdiDex
In one post, Enthalpy wrote

Quote
Electron fall. All s orbitals have their maximum of probability density per volume unit at the nucleus.

But electrons don't concentrate at the nucleus because they are waves and as such, have a volume. And in a more detailed manner: concentrating the electron in a smaller volume implies a higher kinetic energy, which counters the advantage of proximity to the positive nucleus. There is an optimum which is the atom's radius.

In the simple description of the Hydrogen atom, we consider the nucleus as a point particle but in reality, it is not. But what if we consider its size. Then volume element around the nucleus will also increase. From my fuzzy notion, The maxima of the radial probability curve should shift towards the nucleus, since there is a higher volume around the nucleus to start with.

My thought experiment,
What if instead of the nucleus, we take a hollow sphere whose electric field identical (eg. the electric potential at r from the nucleus = electric potential at x from the periphery of this hollow sphere) to the nucleus but has a bigger size. Now the initial volume element will be much bigger than the real case. Will maxima of radial probability will move towards the hollow sphere? Will there be any such case when maxima will be x :rarrow: 0 (like 0.000000001 Å) or rmax  :rarrow: ro ? what if ro > 0.59 Å ?

ro = radius of hollow sphere, assuming potential inside the sphere is infinite so that electron can't go inside.
(Not asking about r, r= ro + x )



 5 
 on: Today at 05:35:40 AM 
Started by Karkzu - Last post by Karkzu
Hi all,

I am chemical engineer and I have got a problem. My problem is exposed concrete primer. Our primer is smell bad and It's precipitation so we can't mix this primer. What can be problem, we don't know..

I'll be glad if you can help me

 6 
 on: Today at 04:52:00 AM 
Started by Samlearner120 - Last post by Enthalpy
Naphthalene too sublimes slowly. Unfortunately, it 's a bit carcinogenic.

Carane maybe? It's a solid and it must be about as volatile as carene
https://en.wikipedia.org/wiki/3-Carene
Camphene is a volatile solid
https://en.wikipedia.org/wiki/Camphene
all these smell strongly.

Cubane is still expensive. Adamantane is said to cost 1$/g
https://en.wikipedia.org/wiki/Adamantane
How fast does hexamethylene tetramine sublime? In a closed package in a cool location it lasts for years, but at heat this may accelerate.
https://en.wikipedia.org/wiki/Hexamethylenetetramine

You can adjust the sublimation rate by the temperature (including direct light) and by the wall thickness of the item.

If a small item evaporates in a year, I don't expect the vapour concentration to be flammable, but the solid itself may be flammable.

Besides sublimation, a solid's molecules could be broken by UV light and the fragments be volatile or reactive to air, but I have no suggestion for that.

 7 
 on: Today at 03:44:35 AM 
Started by Baronwalrus1 - Last post by Enthalpy
Welcome, Baronwalrus1!

What is the unit of R here?

And: what kind of electromagnetic radiation do you expect can make an n=2 to n=4 transition? What are typical frequencies for such radiations? Or wavelengths, if you prefer.

You must know dozens of such guides. Everyone makes mistakes. Scientists wouldn't let a 108 mistake pass through.

 8 
 on: Today at 03:09:43 AM 
Started by CBPQT - Last post by CBPQT
Both reactions will occur simultaneously.
But according to your opinion, which reaction will occur in preference; the one involving the more stable, tertiary carbocation or the other one that involves the less stable, secondary carbocation?

Thanks for showing in interest in my question!

Since the first step is slow, I suppose under thermodynamic conditions, the tertiary carbocation will be the main product. But would you suspect this isomerization is something likely to occur when just dissolving the secondary bromide under standard-ish conditions?

 9 
 on: Today at 12:09:18 AM 
Started by vikram - Last post by vikram

Filter thru celite +Na/K•F(s)

Can you please elaborate the method?

I am using CsF during the reaction. So Is KF/NaF needed?

 10 
 on: Today at 12:07:12 AM 
Started by vikram - Last post by vikram
Have you tried just putting it through a plug of silica instead of running a full column? This is a good way to get rid of salts

@wildfyr you mean to say using Silica as a filtration setup and then again running a full column?

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