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化学反应方程式,简称化学方程式,是用化学式表示化学反应的式子。化学方程式不仅表明了反应物、生成物和反应条件,通过相对分子质量或相对原子质量还可以表示各物质之间的质量关系,即各物质之间的质量比。所以,以化学方程式为依据的相关计算是我们必须把握好的一个知识点。1.反应物质量分数例1(2015年绵阳市中考题)取一定质量的石灰石(所含杂质不溶于水,不与酸反应,高温也不分解),高温煅烧一段时间后得到78 g固体,该固体与400 g溶质的质量分数为14.6%的稀盐酸恰好完全反应后,过滤得到
Chemical reaction equation, referred to as chemical equation, is the chemical formula that chemical reaction. The chemical equation shows not only the reactants, products and reaction conditions, but also the mass relations between the substances, that is, the mass ratio between the substances, by the relative molecular mass or the relative atomic mass. Therefore, the calculation based on chemical equations is a relevant knowledge we must grasp a good point. 1. The mass fraction of reactants Example 1 (Mianyang 2015 senior high school entrance examination questions) to take a certain quality limestone (containing impurities insoluble in water, do not react with acid, high temperature does not decompose), calcined at high temperature for a period of time to get 78 g of solid, The solid and 400 g solute mass fraction of 14.6% diluted hydrochloric acid just exactly, filtered