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【答案】应助回帖
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wchm7125: 金币+30, 翻译EPI+1, ★★★很有帮助 2012-03-31 22:44:00
Controlling the chemical reaction and making it change as expected involve two aspects of the project,
first,whether the reaction can take place ? where is the end ? In other words , it refers to the direction and the limitation of the reaction ---the chemical equilibrium problems. the second, the speed of response-reaction rate. The former are chemical thermodynamics's category, which will be discussed in chapter 4. The latter belongs to the content of the chemical dynamics. This chapter presents the basic knowledge of chemical kinetics. First we introduce the concept of the reaction rate, and discuss the factors that affect the reaction rate from experiment, then this paper puts forward the concept of the activation energy, and shall explain at the molecular level, and then finish cognition of chemical reaction rate from the macroscopic level to microcosmic level for further research and lay the foundation for the application of chemical reaction.
The reaction rate equation must be determined by the experiment.The index of species (namely reaction series α, beta) can not be speculated by stoichiometric number , it can only be determined by experiments . Once the reaction series was determined,the reaction rate coefficient k can be determined . The simplest method of detemining reaction rate equation is the initial rate method.
For most chemical reactions, the reaction rate increases with temperature, few reactions are exception. From the reaction rate equation, it is known that the reaction rate is not only connected with concentration but the coefficient k . The different responses have different rate coefficient; The same reaction in different temperature have different rate of coefficient values. The influence of temperature on the reaction rate are mainly embodied in the temperature on the influence of the reaction rate coefficient. Usually the reaction rate increases with temperature temperature and k value . |
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