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在中考试题中,与化学式有关的题目不少,基本上是两大类型:一是根据各种不同的条件来推断不同物质的化学式;二是利用化学式进行各种计算。本文将从以上两方面入手,进行归类解析,供读者参考。1 根据已知条件推断物质的化学式1.1 根据化合价规律推写化合物的化学式 解这类题的关键是,在任何化合物里,其组成元素中各原子化合价的代数和均为零。 例1.某化合物由A,B,C三种元素组成、其中A为+6价,B为+3价,C为-2价,由A,C 两种元素组成的原子团在该化合物里显-2价,该化合物的化学式为____。
In the mid-term exam questions, there are many questions related to chemical formulae, basically two major types: one is to infer chemical formulas for different substances based on various conditions; the other is to use chemical formulas for various calculations. This article will start with the above two aspects, for classification analysis for readers reference. 1 Inferring chemical formulas based on known conditions 1.1 Chemical formulas for compounds according to the law of valences The key to solving such problems is that in any compound, the algebraic sum of the valence of each atom in its constituent elements is zero. Example 1. A certain compound consists of three elements A, B, and C, in which A is +6, B is +3, C is -2, and the atom group consisting of A and C is shown in the compound. -2 price, the chemical formula of this compound is ____.