“量差法”,人们习惯称之为“差量法”。 在根据化学方程式进行计算的题里,有些题并没有直接给出反应物或生成物的质量,而只是给出了反应前后固体物质的质量或反应前后溶液的质量或反应前后气体的质量,有的是给出反应后固体增加或减少的质量、反应后溶液增加或减少的质量、反应后气体增加的质量,这就给解题带来了难度。这类题若用量差法求解就显得简捷。用量差法求解的关键是根据所发生反应的化学方程式准确地找出符合题意的某反应物和某生成物之间的“量差”,然后再由 “Method of measure difference”, people used to call it “differential method.” In the calculations based on the chemical equations, some questions do not directly give the quality of the reactants or products, but only give the mass of the solid material before and after the reaction or the quality of the solution before and after the reaction or the quality of the gas before and after the reaction. Some of them are The quality of the increase or decrease of the solid after the reaction, the increase or decrease in the mass of the solution after the reaction, and the increase in the quality of the gas after the reaction are given, which makes it difficult to solve the problem. This kind of question is simple and easy to solve by the difference method. The key to solving the difference method is to accurately find the “quantity difference” between a certain reactant and a product according to the chemical equation of the reaction, and then