为了防止错判与误写复分解反应,本文对有关复分解反应的学习说三道四如下:“三”--即发生复分解反应时对生成物所要求的三个条件.一是有沉淀析出;二是有气体放出;三是有水等难电离的物质生成.这三个条件只要具备其中之一,其复分解反应就能发生并趋于完成.例:(1)Na2CO3+Ca(OH)2= In order to prevent misjudgment and mistakenly writing metathesis reactions, this article describes the following reactions related to metathesis reactions as follows: “Three” - namely, the three conditions required for the product to occur during the metathesis reaction. First, precipitation occurs. The second is the release of gas; the third is the formation of water and other difficult ionized substances. As long as one of these three conditions, the metathesis reaction can occur and tend to complete. Example: (1) Na2CO3 + Ca (OH) 2=