一、掌握要求溶质的质量分数的计算是初中化学计算的重点、难点之一，也是中考重点考查内容。对其的要求是：1）应用清质质量分数的概念进行有关的简单计算；2）综合应用化学方程式与清质质量分数的知识进行有关的综合计算。二、有关的基本知识1．溶质的质量分数是溶质质量与溶 First, mastering the calculation of the required mass fraction of solute is one of the key and difficult points of junior high school chemistry calculation, and it is also the key content of the examination. The requirements for it are: 1) apply the concept of clear mass fraction to carry out the relevant simple calculations; 2) comprehensively apply the relevant equations of chemical composition with the knowledge of quality scores of dry matter to carry out comprehensive calculations. Second, the relevant basic knowledge 1. The mass fraction of solute is the mass and solubility of solute