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1、作业：1，2，5，11阅读：AI 26.1 26.2(AII 27.1 27.2)Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.第十二章第十二章 化学动力学基础化学动力学基础Chapte
2、r 12 Fundamental of Chemical KineticsChapter 12 Fundamental of Chemical Kinetics引言： 1. 热力学的作用及没有解决的问题：作用：能量转换，方向和限度，平衡性质计算问题：化学反应快慢反应速率例如： 25标准状态下 2H2(g) + O2(g) 2H2O(l)(1) rGm(1) = -474.4 kJ.mol-1 化学反应的机理 MechanismHCl + NaOH NaCl + H2O (2) rGm(2) = -80 kJ.mol-1Evaluation only.Evaluation only. Creat
3、ed with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.(2) 反应机理2. 化学动力学的任务(1) 反应速率各种因素对速率的影响唯象规律速率理论 微观3. 动力学理论的现状Evaluation only.Evaluation only. Created with Asp
4、ose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.121 基 本 概 念一、反应速率 定义： 0 =BB 单位时间内单位体积中 反应进度的变化。mol.m-3.s-1即(对等容反应)等容反应的速率定义Evaluation only.Evaluation only. Created wit
5、h Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.即等容反应的速率定义(1) r与B的选择无关，但与方程式的写法有关(2) 反应速率的测定：当方程式写定以后，r取决于ct产物反应物Evaluation only.Evaluation only. Created with Asp
6、ose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.二、（基）元反应和反应分子数 (Elementary reaction and molecularity)气相反应H2 + I2 2HI (or 2H2 + 2I2 4HI )机理： (1) I2 2I(2) 2I I2(3) 2I +
7、H2 2HI元反应(写法唯一)反应分子数：在元反应中直接发生碰撞的粒 子数。以双分子反应最多。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.三、简单反应和复合反应 (Simple rea
8、ction and complex reaction)例 I2+H22HI简单反应：机理中只包含一个元反应例 CH2CHCHCH2(丁二烯)+C2H4(乙烯) (环己烯)复合反应：机理中包含多个元反应r = f(c, T, 催化剂，溶剂，光)，以下分别讨论Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 20
9、04-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.122 物质浓度对反应速率的影响一、速率方程 定义：描述rc 的关系式例： I2+H22HI r = kH2I2Cl2+H22HCl r = kH2Cl20.5Br2+H22HBr(1) 速率方程有两种形式：rc微分式 ct 积分式Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for
10、 .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.(2) 速率方程的作用：动力学学习，工程 设计，机理研究。(3) 速率方程的确定：实验。所以，速率方程是经验方程。二、元反应的速率方程质量作用定律对元反应 aA + bB P 则 r = kAaBb The Law of Mass ActionEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 C
11、lient Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.三、反应级数和速率系数许多反应的速率方程可表示成幂函数形式(1) 、 、：分级数，表示各物质 浓度对r的影响程度。 n = + + +：反应级数。n与反应分子数的意义、数值特点均不同。(Reaction order and rate coefficient)Evaluation only
12、.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.(2) k：速率系数 意义：各物质浓度均为1mol.m-3时的r 与浓度无关，k=f(T，催化剂，溶剂等) k的单位决定于反应级数：例：n=1, s-1；n=2, m3.
13、mol-1.s-1123 具有简单级数的化学反应 若0, 1, 2, 3, n=1，称一级反应，n=2，称二级反应，等等。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.一、一级反应例A
14、B + C a(mol.m-3)00t=0 tcAEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.即令y为反应物A的消耗百分数，则 cA=(1-y)alncA slope=-kt特点：(1
15、) k单位：s-1, min-1, h-1(2) lncAt呈直线 且 slope = -k(3) 半衰期：y = 1/2半衰期与初始浓度无关Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.二、二级反应例A + B P a0t=0 t二级反应： =1, =1 b a-xb-xx则1. 若a =b： 则Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd
