Sciencemadness Discussion Board

NaOH as drying agent?

KidCurry - 12-8-2005 at 03:43

Is sodium hydroxide pellets/potassium hydroxide flakes suitable as a drying agent for amines solved in for example toluene or xylene? Did not find any MgSO4 locally and don't want to order (because of minimum order/shipping costs).

vulture - 12-8-2005 at 04:26

There shouldn't be a problem with free amines.

neutrino - 12-8-2005 at 05:35

You really can't find epsom salts?:o

KidCurry - 12-8-2005 at 06:36

Well I can, but it's sold at the pharmacy in really small quantaties and pretty expensive (I'm not cheap, just damn poor :D). Of course I can order it off an chemical supplier but then I have to order for atleast 125USD and pay 40USD for postage... I live in a small town, and there really isn't any easy way to get hold of any chemicals at all around here and since I need KOH/NaOH anyway I'd rather use them for drying if suitable.


[Edited on 12-8-2005 by KidCurry]

[Edited on 12-8-2005 by KidCurry]

bio2 - 16-8-2005 at 23:05

KOH & NaOH are the preferred drying agents for free amines. Dries much more complete than MgSO4.

Make damn sure the amine and solvent are clean or you may have a color reaction. Normally the pellets are used to dry the isolated base after distilling.

praseodym - 17-8-2005 at 23:31

Sodium hydroxide pellets are normally used as they are more effective in drying amines than magnesium sulphate. Sodium hydroxide dries compounds through absorption and solution formation, while magnesium sulphate dries by hydration.

unionised - 18-8-2005 at 12:03

Amines react with mag sulphate in some cases.