石灰水的制备和保存黎书平（北京顺义县城关一中１０１３００）在中学化学实验教学中，多次用到石灰水，是实验室中常备试剂之一．用过滤方法制得的石灰水实验效果好，但不易保存，长时间放置，就会失效．通过多次实践，我发现用静置沉淀的方法制取石灰水效果更好．具体做... Preparation and preservation of lime water Li Shuping (101300, Guanzhong Yizhong, Shunyi County, Beijing) used lime water several times in the middle school chemistry experiment teaching, and was one of the standing reagents in the laboratory. The lime water obtained by the filtration method has good experimental results, but it is not easy to preserve, and it will fail if it is left for a long time. Through repeated practice, I found that using standing sedimentation method to obtain lime water is better. Specific to do...