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一、苯酚和浓澳水反应的投影实验 原理 苯酚和浓溴水反应生成三溴苯酚的白色沉淀,这个反应本来是很灵敏的,甚至10ppm浓度的苯酚溶液也可用此实验检验出来。但是由于溴苯酚能溶解在苯酚溶液里,如果把试管稍一振荡白色沉淀就消失,如果在准备实验时苯酚溶液配得较浓时实验往往会失败,所以在做此实验时要配制很稀的苯酚溶液,浓度应小于0.125％。另外溴水要浓,为了增加可见度,可采用投影及对比试验的教学方法。
First, the projection experiment of the reaction of phenol and concentrated Australian water Principle The reaction of phenol and concentrated bromine water to produce a white precipitate of tribromophenol, this reaction was originally very sensitive, even 10ppm concentration of phenol solution can also be used to test out. However, since the bromophenol can be dissolved in the phenol solution, if the test tube is slightly shaken, the white precipitate disappears. If the phenol solution is more concentrated in the preparation of the experiment, the experiment will often fail, so it is very rare to prepare the experiment when preparing the experiment. Phenol solution, the concentration should be less than 0.125%. In addition, the bromine water should be concentrated. In order to increase the visibility, teaching methods of projection and contrast experiment can be used.