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化学鉴别题是历年来中考的热点题型.此类试题主要考查各类物质之间的反应,综合性较强,难度较大。因为能够考查同学们的实验设计能力、综合分析问题的能力及创新能力而备受青睐。下面结合2007年各地中考试题进行分类举例分析,供同学们参考。一、不加其他试剂鉴别型解题策略1.先根据被鉴别物质的物理性质,找出有特殊颜色或气味的一种物质,并用这种物质作鉴别试剂与其他物质混合,若再有一组特殊现象
The chemical identification question is a hot topic question in the middle school entrance examination over the years. Such examination questions mainly examine the reactions among various substances, and the comprehensiveness is strong and difficult. It was favored because it was able to examine the students’ experimental design ability, ability to comprehensively analyze problems, and innovation ability. In the following, we will use the examples of the various local examinations in 2007 as examples for analysis by students. First, without other reagents identification type problem-solving strategy 1. First, according to the physical properties of the identified material, to find a substance with a special color or odor, and use this substance as a differentiation reagent mixed with other substances, if there is a group Special phenomenon