一、乙醛还原氢氧化铜实验 如果按高中化学课本(乙种本)下册,第199页[实验7～6]所讲方法进行实验,实验现象不明显,得到的Cu_2O沉淀不是红色而是棕色或黑色,这与课本所述不符。这对学生认识乙醛的化学性质和今后的学习,造成不良的影响。因此,改进如下: First, the acetaldehyde reduction of copper hydroxide experiments If you press the method described in the high school chemistry textbook (type B) book, page 199 [experiment 7 ~ 6] to experiment, the experimental phenomenon is not obvious, the Cu2O precipitate obtained is not red but Brown or black, this is not consistent with the textbook. This has an adverse effect on students’ understanding of the chemical nature of acetaldehyde and its future learning. Therefore, the improvement is as follows: