Re: ORGLIST: Solvent Info

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From: srinivas reddy (gounisrinivas$##$yahoo.com)
Date: Mon Oct 10 2005 - 10:01:53 EDT


hi,
When we wish to extract a particular compound, or
group of compounds, it is not usually effective simply
to choose an extraction solvent at random. Typical
extraction solvents would include water, alcohols,
dichloromethane (methylene chloride), diethyl ether,
and hexane etc....

Each substance we wish to extract will not be equally
soluble in each solvent. Choosing a solvent in which
our compound of interest is highly soluble will ensure
we obtain high extraction yields; however, we may also
extract, in the process, many compounds which we would
consider to be impurities, and which we would rather
leave behind during the extraction procedure.

At 25 degrees C, 1.0 gram of caffeine will dissolve in
8.1 mL of chloroform, in 47 mL of water, in 86 mL of
benzene, or in 370 mL of diethyl ether. Hence,
caffeine is most soluble in chloroform—almost six
times as soluble in chloroform as it is in water. If
we were only interested in obtaining the caffeine we
could extract it using chloroform.

books like
1)"Handbook of Solvents", ChemTec Publishing company,
by Wypych, G.

2) "Solvents and Solvent Effects in Organic Chemistry"
by Christian Reichardt

3)Handbook of Solvents, Second Edition
compiled by Michael and Irene Ash

4)Industrial Solvents Handbook (5th Edition)
By: Flick, E.W. © 1998 William Andrew Publishing/Noyes

might be helpful.

good luck

srinivas
--- Madhu Rao <raom_dtpi$##$yahoo.com> wrote:

> Hi,
>
> Could you please suggest where I might find
> information on solvents. How to choose solvents etc.
> I
> am performing an experiement to extract caffeiene
> (aq)
> and trying to determine why chcl3 is a better
> solvent
> than hexane.
>
> Thanks!
>
>
>
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G.S.Reddy



                
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