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The Hive => Chemistry Discourse => Topic started by: Elementary on January 27, 2002, 02:45:00 AM

Title: Drying Agent
Post by: Elementary on January 27, 2002, 02:45:00 AM
I have heard that magnesium perchlorate is an extremely good drying agent, but I can't find any chemistry book references on ways of making it.

Is Mg(CLO4)2 made the same way as potassium perchlorate is made, by heating potassium chlorate ?

Anybody got any good text book synths for me while I'll plough though the patent office site ?
One day I'll understand everything !
Title: Re: Drying Agent
Post by: PPyroReached600 on January 27, 2002, 02:48:00 AM
Couldn't you use ion exchange between MgSO4 and NaClO4?

NaX exchanges with lots of sulfates.
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Title: Re: Drying Agent
Post by: Elementary on January 27, 2002, 03:06:00 AM
would the sodium perchlorate not oxidise the Magnesium sulphate to a persulphate ?

Oh no that does not balance ! :P

Yes seems a great method !  :)
One day I'll understand everything !
Title: Re: Drying Agent
Post by: Elementary on January 27, 2002, 03:10:00 AM
Is magnesium perchlorate a powerfull enough dehydrator to  pull H2O's away from organic chemicals, like turning amide's into nitriles ?
One day I'll understand everything !
Title: Re: Drying Agent
Post by: PPyroReached600 on January 27, 2002, 03:15:00 AM
Still going for acetamide --> acetonitrile?  :)

I don't know on the MgClO4. What about phthalic anhydride?

                                                   PrimoPyro
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Title: Re: Drying Agent
Post by: PolytheneSam on January 27, 2002, 03:24:00 AM
You can make P2O5 by heating a phosphate salt with sand (no carbon).
http://www.geocities.com/dritte123/PSPF.html
Title: Re: Drying Agent
Post by: PPyroReached600 on January 27, 2002, 03:27:00 AM
How hot?
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Title: Re: Drying Agent
Post by: Elementary on January 27, 2002, 03:33:00 AM
No I'm not going for acetonitrile, I just used it as an example.

Just wanted to know just how powerfull a dehydrating agent magnesium perchlorate is.
One day I'll understand everything !
Title: Re: Drying Agent
Post by: PolytheneSam on January 27, 2002, 03:53:00 AM
>How hot?

Very hot.  From what I can remember from reading about it, about the same temperatures as making phosphorus.
http://www.geocities.com/dritte123/PSPF.html
Title: Re: Drying Agent
Post by: terbium on January 27, 2002, 05:51:00 AM
Don't use magnesium perchlorate as a drying agent. Organic materials in contact with magnesium perchlorate will spontaneously combust. Magnesium perchlorate is used as a drying agent only in a special case - the absorption train of an elemental analysis rig.