O.K..... Here's what I heard-- Dry some epsom salt in the oven. Put it in a funnel and pour some non polar solvent through it. This will "suck" the water out of the solvent creating an anhydrous solvent. Is this true? It sounds ridiculous to me.

I don't believe water would be in a nonpolar
solvent in the first place

Yes this is true except that the solvents won't be anhydrous, they will be dry for most purposes, but not for doing a grignard or LAH reduction. To make totally anhydrous solvents they must be dried over sodium or phosphorus pentoxide or something equally powerful.

Some salts adhere strongly to waters of crystallization so much that when they are dehydrated they will suck water out of a solvent. Magnesium sulphate isn't quite anhydrous until it gets to red heat which is over 300 C. But oven dried stuff works fine.

Yes non-polar solvents do hold some water, toluene holds a small amount, small enough to mess things up, and something like ether can hold a lot of water!!

Thank you! I really like reading your stuff. Maybe you were a teacher in another lifetime(or maybe this one).

Molecular seives are really good at making things anhydrous. Toluene can be dried without anything else. Water and toluene form an azeotrope that boils at a lower temp than water or toluene. Basically, toluene can be dried by simply boiling some of it's volume off (depending on water content of course).