Rectification: Alcohol, water and sulfuric acid are present in the form of impurities in ether obtained from the above method. To remove sulfuric acid, the obtained ether is washed with a solution of sodium dioxide.
To remove alcohol, ether is mixed with 50% calcium chloride solution and left for some time, forming crystals of CaCl2.3C2H5OH. They are filtered and separated.
To remove water, it is dried by adding anhydrous calcium chloride to the ether, thus distilling the obtained ether at 35°C to obtain pure ether.