一级反应动力学、二级反应动力学基本原理.pptx

Kinetics动力学; Rate of reaction is typically measured as the change in concentration (moles/L) with time 反应速率通常通过浓度(mol/L)随时间的变化来测量 This change may be a decrease or an increase 改变可能是增加的也可能是减小的 Likewise the concentration change may be of reactants or products 同样，改变浓度的物质可能是反应物也可能是生成物; Rate has units of moles per liter per unit time - M s-1, M h-1 速率的单位是摩尔每升每单位时间，如M s-1、M h-1 Consider the hypothetical reaction 对于这个假设的反应 aA + bB ? cC + dD We can write; Note the use of the negative sign 注意负号的使用 - rate is defined as a positive quantity 反应速率被定义为正量 - rate of disappearance of a reactant is negative 那么，反应物的消耗速率就是负的 2N2O5(g) ? 4NO2(g) + O2(g); Rate may be expressed in three main ways: 反应速率主要有以下三个表达方式： Average reaction rate: a measure of the change in concentration with time 1、平均反应速率：浓度随时间变化的度量 2. Instantaneous rate: rate of change of concentration at any particular instant during the Reaction 2、瞬时速率：反应过程中某一特定瞬间的浓度变化速率 3. Initial rate: instantaneous rate at t = 0 - that is, when the reactants are first mixed 3、初始速率：t=0时即反应物最初混合时的瞬时速率，;Rate Laws 速率定律;;Rate Laws;First order reactions一级动力反应;t? = 0.693 / k;Example of 1st order reaction1级动力反应范例;Second Order Reaction二级动力反应;t? = 1 / k [Ao];Example of 2nd order reaction二级动力反应范例;Pseudo first order reactions伪一级反应;Reaction Mechanism反应机理;Single Step (Elementary) Reaction Process单步（基本）反应过程;Rate Laws For Elementary基本反应速率定律;Reaction order is not necessarily related to the stoichiometry of the reaction, unless the reaction is elementary. 反应级数不一定和反应的化学计量数有关，除非反应是基本反应 In single step process, reaction order = coefficient of reactant in chemical equation 在单步反应过程中，反应级数=化学式中反应物的系数 Complex reactions may or may not have reaction orders equal to their stoichiometric coefficients 复杂反应的反应级数可能和化??计量系数相等 Not all first order reactions, are single step, monomolecular reactions 不是所有的一级反应都是单步反应、单分子反应;Overview of Elementary Reactions基本反应回顾;Arrhenius Equation and Transition State Theory阿伦纽斯方程和过渡态理论;Increased Temperature = Fa