2 Attention 1. When heating to reflux, start the reflux slowly 2. When adding sodium carbonate powder to neutralize the acid, slowly add and stir 3. When distilling diethyl ether, avoid open flames, and connect a rubber tube to the drain pipe at the end of the pipeAttention 1. When heating to reflux, start the reflux slowly！ 2. When adding sodium carbonate powder to neutralize the acid, slowly add and stir！ 3. When distilling diethyl ether, avoid open flames, and connect a rubber tube to the drain pipe at the end of the pipe！