Question

Is there a reaction between Na2SO4 with Ch2Cl2? We did a caffeine extraction from tea bags and we are asked why the Na2So4 was added (to remove water I learned) and if a reaction took place. Can someone help? Thanks!

Answer 1

Anhydrous Na2SO4 does not react with CH2Cl2. It simply removes traces of water from the solvent, CH2Cl2, by forming a hydrate of Na2SO4 which settles to the bottom. Moisture in the dichloroethylene solvent could contaminate the caffeine residue after the solvent evaporates.

Answer 2

Did you use anhydrous Na2SO4? It form a decahydrate easily.
Na2SO4 + 10H2O ==> Na2SO4*10H2O.
The heptahydrate is known, also.

Answer 3

Thanks for the help! It is much clearer to me.