Ether distillation, in the instrument assembly and operation process should pay attention to what problems

When using or distilling ether in the laboratory, open flame is strictly prohibited near the laboratory bench. Because ether is volatile and flammable, and air mixed to a certain proportion of the explosion. So distillation of ether, can only be heated with a hot water bath, distillation device should be tightly sealed without air leakage, the receiver branch pipe connected to the rubber tube should be introduced into the sink or outdoor, and the receiver outside the cooled with ice water.

In addition, when distilling ether that has been stored for a long period of time, it should be tested for the presence of peroxides. Because the ether in contact with air and light exposure during storage may produce diethyl peroxide (C2H5OOC2H5), peroxide is easy to explode by heat. Test method: take a small amount of ether, add an equal volume of 2% KI solution, and then add a few drops of dilute hydrochloric acid shaking, shaking the solution if the starch can make the blue, it shows that there are peroxides. Removal of peroxide compounds: in the liquid separatory funnel add ether (containing peroxide), add quite ether volume 1/5 of the newly prepared ferrous sulfate solution (55 ml of water plus 3 ml of concentrated sulfuric acid, then add 30g of ferrous sulfate), and vigorously vibrate to separate the aqueous layer can be.