中考化学推断题中,物质推断题占有重要位置,解这类题有个共同点,就是以特征性质,特征反应现象为突破口,向前或向后推,即可得到结论。 常见的特征性质、特征反应现象有: ①溶于水显碱性的气体只有NH_3; ②空气中能自然的固体物质只有白磷; In the chemistry extrapolation question of the senior high school entrance examination, the question of material extrapolation occupies an important position. To solve this kind of question has one thing in common, that is, the nature of the feature, the characteristic reaction phenomenon as a breakthrough, pushing forward or backward, you can reach a conclusion. Common characteristics of the nature of the characteristics of the reaction phenomenon are: 1 dissolved in water alkaline gas is only NH 3; 2 natural solids in the air only white phosphorus;