现行九年义务教育三年制初级中学化学教科书第189页有这样一道复习题:有一包白色固体,可能是氯化钙和碳酸钠的混合物,也可能只含其中一种物质。为了鉴别它,做了下列实验:(a)取一些白色固体溶解在水里,有白色沉淀生成。把悬浊液过滤,滤液无色。(b)在滤出的沉淀里加入盐酸,有无色气体生成。该气体能使澄清的石灰水变浑浊。 The current nine-year compulsory education three-year junior middle school chemistry textbook page 189 has such a review question: There is a pack of white solids, which may be a mixture of calcium chloride and sodium carbonate, or may contain only one of them. To identify it, the following experiments were performed: (a) Take some white solid dissolved in water and a white precipitate formed. The suspension was filtered and the filtrate was colorless. (b) Hydrochloric acid is added to the precipitated precipitate, and a colorless gas is generated. This gas can make the clarified lime water turbid.