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高中化学课本(甲种本)第三册115页[实验3—3]在盛有少量苯酚溶液的试管中,滴入过量的浓溴水,可以观察到很快有白色沉淀生成。此处叙述表明白色沉淀的产生条件是要加入过量的浓溴水。在同书209页则有这样一段话:“向透明苯酚溶液里加入浓溴水,加到有白色浑浊现象出现为止。”这就是说,向苯酚溶液中加入的浓溴水,应该是适量的,不须要过量。教材前后对同一问题的表述不统一,这有碍教学。
High School Chemistry Textbook (A kind) The third volume, 115 pages [Experiment 3-4] In a test tube containing a small amount of phenol solution, an excessive concentration of bromine water was added dropwise, and white precipitates were quickly observed. The description here indicates that the white precipitate is produced by adding an excess of concentrated bromine water. In the same book, on the 209th page, there is such a paragraph: “Add concentrated bromine water to the transparent phenol solution and add white turbidity.” That is, the concentration of bromine added to the phenol solution should be an appropriate amount. There is no need to overdo it. The presentation of the same question before and after the textbook is not uniform, which hinders teaching.