日前笔者去一所学校听课,教学课题是“溶液酸碱性强弱”。对于课堂观察到的一些现象以及关于如何进行该课题的教学颇有想法,现整理出来,供同行参考。一、酸碱性强弱的引出在前一节课上,学生已经学过酸碱指示剂的知识,知道用石蕊试液、酚酞试液、石蕊试纸可以方便地检测出溶液的酸碱性。教师与学生一起回顾了这些知识之后,问学生:“用指示剂对溶液进行检测,存在什么缺陷?”有的学生回答说:“用指示剂检测溶液,只能判断溶液是酸性还是碱性,但无法判断酸碱 A few days ago I went to a school lectures, teaching topics is ”acid strength of solution “. Some of the observed phenomena in the classroom and the idea of ​​how to carry out the teaching of the subject, now sorted out for peer reference. First, the strength of acid-base leads In the previous lesson, students have learned the knowledge of acid-base indicator, know with litmus solution, phenolphthalein test solution, litmus test paper can easily detect the solution of acid Sex. After reviewing this knowledge with the students, the teacher asks the student: ”Something flawed in testing the solution with an indicator?“ Some students replied: ”The indicator solution is used to determine whether the solution is acidic or not Alkaline, but can not judge acid