2. The reaction of sodium alcohol and dried hydrogen sulfide to make sodium sulfide:
In a 150 ml flask of branch pipe, add 20 ml new distillation of anhydrous ethanol and 2 g sodium metal pieces of smooth surface without oxidation layer, the flask is installed on the reflux condensation pipe and drying, first branch closed. When sodium alcohol is precipitated, add about 40 ml of anhydrous ethanol in batches.
Through the branch tube, a glass tube is inserted into the bottom of the solution to the dry hydrogen sulfide gas (note that the sealed branch cannot have air into the flask). To saturate the solution. Filter the solution to remove the precipitate. To save the filtrate in the conical flask of dry, add 50 ml absolute ethyl ether, immediately there is a lot of NaHS white precipitate out, placed a period of time, then give some time to join the ether, until no longer appear white upper solution precipitation. A total of about 110mL of ether. The precipitate is quickly filtered out and washed in absolute ether by 2 ~ 3 times, sucking dry, in a vacuum dryer. The purity of the product can be analyzed pure. If the NaHS of higher purity can be dissolved in ethyl ether with ethanol.