[电解池金属的电化学腐蚀与保护.ppt

答案　D 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. 2．(2012·浙江理综，10)以铬酸钾为原料，电化学法制备重铬酸钾的实验装置示意图如下： 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. (2)析氢腐蚀与吸氧腐蚀 以钢铁的腐蚀为例进行分析： 条件 电极 反应 总反应式 联系 负极 正极 析氢腐蚀 更普遍 吸氧腐蚀 水膜酸性较强 (pH≤4.3) 水膜酸性很弱或呈中性 Fe－2e－===Fe2＋ 2H＋＋2e－===H2↑ O2＋2H2O＋4e－ ===4OH－ Fe＋2H＋===Fe2＋＋H2↑ 2Fe＋O2＋2H2O ===2Fe(OH)2 吸氧腐蚀 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. 铁锈的形成：4Fe(OH)2＋O2＋2H2O===4Fe(OH)3，2Fe(OH)3===Fe2O3·xH2O(铁锈)＋(3－x)H2O。 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．金属的防护 (1)电化学防护 ①牺牲阳极保护法— 原理 a． ：比被保护金属活泼的金属；b. ：被保护的金属设备。 ②外加电流的阴极保护法— 原理 a． ：被保护的金属设备；b. ：惰性金属。 (2)改变金属的内部结构，如制成合金、不锈钢等。 (3)加防护层，如在金属表面喷油漆、涂油脂、电镀、喷镀或表面钝化等方法。 原电池 负极 正极 电解 阴极 阳极 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. 影响金属腐蚀的因素有哪些？ 提示　影响金属腐蚀的因素包括金属的本性和介质两个方面