[2012高考化学复习基础提高课件：第四章第二节富集在海水中的元素——氯.pptVIP

2．在氯水中存在多种分子和离子，它们在不同的反应中表 现各自的性质．下列实验现象和结论一致且正确的是 (　　) A．向氯水中加入有色布条，一会儿有色布条褪色，说 明溶液中有Cl2存在 B．溶液呈黄绿色，且有刺激性气味，说明有Cl2分子存 在 C．先加入盐酸酸化，再加入AgNO3溶液产生白色沉淀， 说明溶液中有Cl－存在 D．加入NaOH溶液，氯水黄绿色消失，说明有HClO分 子存在 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 解析：氯水中使有色布条褪色的是HClO分子；呈现黄绿色的是Cl2分子；与AgNO3反应生成白色沉淀的是Cl－，但前提是不能加入盐酸酸化(引入了Cl－)；加入NaOH溶液，中和HCl和HClO，使氯气与水的反应平衡Cl2＋H2O H＋＋Cl－＋HClO正向移动，黄绿色消失． 答案：B Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3．收集方法 向上排空气法或排饱和食盐水法． 4．净化方法 用饱和食盐水除去HCl，再用浓H2SO4除去水蒸气． 5．尾气吸收 用强碱溶液(如NaOH溶液)吸收． Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 6．验满方法 (1)将湿润的淀粉碘化钾试纸靠近盛Cl2的瓶口，观察到试纸 立即变蓝，则证明已集满． (2)将湿润的蓝色石蕊试纸靠近盛Cl2的瓶口，观察到试纸立 即发生先变红后褪色的变化，则证明已集满． (3)实验室制取Cl2时，常常根据氯气的颜色判断是否收集满． Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 7．注意事项 (1)为了减少制得的Cl2中HCl的含量，所