将一定量某种试剂加入到含可与之反应的几种物质的混合溶液中,确定反应的先后顺序,在某些解题中十分重要.在解题中运用物质(或离子)共存原理,通过反应过程的分析,能明确其反应顺序,进而达到求解的目的.这是所有类似问题的解决通法.下面试作例析: Adding a certain amount of a reagent to a mixed solution containing several substances that can react with it, and determining the order of the reactions, is very important in some problem solving. The principle of coexistence of substances (or ions) is used in the problem solving. Through the analysis of the reaction process, the reaction sequence can be clarified and the purpose of the solution can be achieved. This is the solution to all similar problems. The following sample analysis is given: