ORGLIST: Brine strikes again

Date view Thread view Subject view Author view Attachment view

From: Witek Mozga (mozga$##$trimen.pl)
Date: Sun May 06 2001 - 07:36:48 EDT


Hello again,

I would like to thank all the people who answered my question about
brine. However most answers suggested that brine does not possess
any drying properties. I often read something like this:

> Brine will not dry anything.

or

> it would seem
> obvious that one cannot dry something by adding water.

I don`t think so. Of course one cannot dry something by adding water
but brine is not just water but saturated solution of salt.
Water has good solubility in ether (14g/L) or ethyl acetate (33g/L).
Just imagine: you shake neat water with ether. One can be sure that
several grams of water will be absorbed in the organic phase.
Now you shake another portion of ether with saturated brine. I don`t
think that water will migrate into ether because one could observe salt
precipitation. I performed such experiment and did not observe this
phenomenon. This mean that bine is "less moisture" than pure water.
Maybe it is "less moisture" to such degree that it already can dry
organic phase? (Remember osmosis? This might be similar.) However
what would happen if you shook moisture ether with saturated brine? I
guess that some water would be extracted from the organic phase,
because water "likes" polar brine and has low affinity to lipophilic
ether. I think this is a kind of equilibrium.
Well, to decide who is right one should perform an experiment. Just
measure the content of water in organic solvent prior to and after it was
shaken with brine. Unfortunately I cannot do it and can only say what I
think. Maybe some of you can?

Best regards,

Witek


Date view Thread view Subject view Author view Attachment view

This archive was generated by hypermail 2.1.4 : Fri Sep 19 2003 - 12:16:28 EDT