化工专业英语Lesson-2.doc

PAGE \* MERGEFORMAT 13 Lesson2 Chemical Equilibrium and Kinetics 化学平衡和动力学 A1 A major objective of chemist is to understand chemical reactions, to know whether under a given set of conditions two substances will react when mixed, to determine whether a given reaction will be exothermic or endothermic, and to predict the extent to which a given reaction will proceed before equilibrium is established. 化学家的一个主要目标是理解化学反应，知道在一组给定的条件下两种物质混合时能否发生反应；确定一个给定的反应是放热还是吸热；预测一个给定的反应在平衡前进行的程度。 2 An equilibrium state, produced as a consequence of two opposing reactions occurring simultaneously, is a state in which there is no net change as long as there is no change in conditions. 平衡状态是由两个对立反应同时发生产生的结果，在平衡状态下，只要条件不发生改变，这个状态就不会有净变化。 3 In this lesson it will be shown how one predict the equilibrium state of chemical systems from thermodynamic data, and conversely how the experimental measurements on equilibrium states provide useful thermodynamic data. 在这节课中，将会展示如何根据热力学数据来预测化学体系的平衡状态，以及相反地，平衡状态下的实验测量值如何提供有用的热力学数据。 4 Thermodynamics alone cannot explain the rate at which equilibrium is established, nor does it provide details of the mechanism by which equilibrium is established. 仅凭热力学无法解释平衡建立的速度，也不能提供平衡建立的详细的机理。 5 Such explanations can be developed from considerations of the quantum theory of molecular structure and from statistical mechanics. 从分子结构的量子理论和统计力学的角度考虑可以使这样的解释得到发展。 B1 To appreciate fully the nature of the chemical equilibrium state, it is necessary first to have some acquaintance with the factors which influence reaction rates. 要充分理解化学平衡状态的本质，首先需要对影响反应速率的因素有一定的了解。 2 The factors which influence the rates of a chemical reaction are temperature, concentrations of reactants(or partial pressures of gaseous reactants), and presence of a catalyst. 影响化学反应速率的因素有温度、反应物浓度（气体反应物的分压）和催化剂。 3 In general, for a given reaction the higher the temperature, the faster the reaction will occur. 通常，对于一个给定的反应，温度越高，反应发生的越快。 4 The concentrations of reactants or partial pres