化学计算不仅是一种定量研究化学物质间相互反应的科学研究方法,同时也是帮助学生提高化学解题灵活性和增强逻辑思维能力的非常有益的途径。化学计算中常见的是过量计算,然而过量的判断经常让很多学生困惑,由于事前并不能确切地知道哪一种物质过量,所以很多学生觉得无从下手。我认为,对于过量的化学计算,其解题方法都是类似的,具有普遍性。如果我们事先无法确定哪一种物质是过量的,那就采用一分为二(或一分为三)的系统分析方法进行讨论,也就是说,对于所有可能的情况都加以详细的分析、周密的讨论,直到得出结论(通过这样的训练可以有效 Chemical calculation is not only a scientific research method for quantitatively studying the interaction between chemical substances, but also a very useful way to help students improve their flexibility in solving problems and enhance their logical thinking skills. Common calculations in chemical calculations are over-calculations. However, excessive judgments are often confusing to many students. Since many substances are not known exactly beforehand, many students find it impossible to start. I think that for over-stoichiometric calculations, the problem-solving methods are similar and universal. If we cannot determine in advance which substance is excessive, we will use a system analysis method that is divided into two (or divided into three), that is, detailed analysis and careful analysis of all possible situations. Discussion until it is concluded (through such training can be effective