在现行的初中化学教材中,水和酒精混合实验,酒精用量大,效果不明显;虽已经有人对此实验做了改进,但还是难以推广。对此,我们重新设计了两种实验装置,收到了良好的效果。一、教具Ⅰ的使用1.装配及配套仪器取一支20 mm×200 mm 的试管(其容积约40mL),配一单孔橡皮塞子,孔内插入一支长约20 cm的普通玻璃管(直径为7mm～8 mm);然后在导管上 In the current junior high school chemistry textbook, the mixed experiment of water and alcohol has a large amount of alcohol and the effect is not obvious; although some people have already made improvements to this experiment, it is still difficult to promote. In this regard, we redesigned two experimental devices and received good results. First, the use of teaching aids I. Assembly and supporting equipment to take a 20 mm × 200 mm test tube (the volume of about 40mL), with a single hole rubber stopper, insert a common glass tube about 20 cm in length ( Diameter 7mm～8mm); then on the catheter