用乙醛做银镜反应的实验，教材中虽列出了具体的实验步骤，但笔者在实验过程中发现成功率较低，若将实验过程稍加改动，实验成功率可达95％以上。如果用pH试纸测试一下乙醛，就会发现乙醛显酸性。因为乙醛溶液容易发生聚合反应，聚合成三聚乙醛或四聚乙醛，而聚合后的乙醛不发 Using acetaldehyde as a silver mirror reaction experiment, the textbook listed specific experimental steps, but the author found that the success rate was low during the experiment. If the experiment process is slightly modified, the experimental success rate can reach more than 95%. If acetaldehyde is tested with a pH test paper, acetaldehyde is found to be acidic. Because the acetaldehyde solution is prone to polymerization, it is polymerized into paraldehyde or acetaldehyde, but the acetaldehyde after polymerization does not