I don't understand the difference between osmolarity and osmolality. I've read 4 pages describing the difference but still can't get it.

@CowperKettle osmolarity is the amount of osmoles per liter solution, osmolality is the amount of osmoles per kg of solvent (be careful, not kg of solution)

It's described here: en.wikipedia.org/wiki/Plasma_osmolality

@CowperKettle I can tell you the similarity: the terms should both burn in hell.

Thank you!

Hello! If this is SN2 reaction then how can I see where is inversion of structure?

@ABcDexter I am from India. What’s the deal.

@Fawad You can't. There's no stereocenter.

@Zhe so every SN2 reaction don’t show inversion?

They all invert

But you have to have a stereocenter to observe the inversion

But just because you can't observe it doesn't mean it doesn't happen

Technically, your question is ambiguous

By stereo entree you mean chiral centre or something else?

Because you have formal inversion versus actual inversion

Actual inversion always happens

Formal inversion can't happen because it's not a stereocenter

Stereo centre=chiral centre?

yes

@Zhe not always

Hey @zhe I need your help

“ can you explain why is bimolecular dehydration not apppropriate for the preparation of ethyl methyl ether?”

i think we can prepare.. but I am wrong. I searched on internet but nothing goes in mind

It's a mixed either

And your proposal doesn't allow for the non mixed products

50% yield at best seems pretty bad

> It is because in step 2 of the reaction, the departure of leaving group (HO–CH3) creates a more stable carbocation [(CH3)3C+], and the reaction follows SN1 mechanism.

What does it mean? ^

@zhe are you online then help

@Fawad I find this statement extremely obnoxious. Maybe it's just a language issue, but please avoid this tone in the future.

@Zhe sorry if I was Lolcat for sometime.

My mothertounge isn’t English so please cope with me.

@Fawad I'm not really sure how this statement is unclear. If so, you should definitely review mechanisms for SN1 and SN2.

Unfortunately, I've been doing this long enough that it's very hard for me to understand difficulties beginners have because I can't fathom their assumptions and thought processes.

I might be able to help you, but you need to provide more that just this line

In that example how leaving group (HO-CH3) creates a more stable carbocation [(CH3)3C+]. If (HO-CH3) leaves then isn’t remaining group is[CH3CH2]^+

Or remaining group react with I^- and forms CH3CH2I

I don't understand that question

You have two choices, you can make t-butyl cation or methyl cation

The t-butyl cation is more stable