化学计算作为初中化学知识的重要组成部分,如计算相对分子质量,物质中某种元素的质量分数,溶液中溶质的质量分数,根据化学方程式的简单计算等计算题频频在中考试题中出现,旨在考查同学们能否在理解与掌握基础知识的前提下综合运用化学知识理论原理进行求解。现就同学们在解答计算类题目时存在的常见问题,作如下简要评析。一、相对分子质量的计算 Chemical calculations as an important part of junior high school chemistry knowledge, such as the calculation of relative molecular mass, mass fraction of a substance in the material, the mass fraction of solute in solution, according to the simple calculation of chemical equations and other calculation questions frequently appear in the examination questions, In the test students can understand and master the basics under the premise of comprehensive use of chemical knowledge theory to solve. The students are now answering questions in the calculation of common problems, make the following brief comments. First, the calculation of relative molecular mass