摘要
分析了物理化学中学生容易混淆或犯错的3个案例.[案例1]若从同一始态出发,理想气体经过绝热可逆膨胀和绝热不可逆膨胀2条途径,分别到达相同体积时的终态,其温度、压力的大小如何比较？这个问题的解答不能用最大功原理,因为终态不同,用熵增加原理解释更为科学;[案例2]关于二级反应2A→B,其速率常数及半衰期的计算问题;[案例3]水蒸馏时存在过热现象,要蒸出某个直径的小气泡需要过热多少度？这个问题的解答要用到克劳修斯-克拉贝龙方程,探讨了方程中压力如何取值及代表的意义.
This paper analyzed three typical examples of physical chemistry that students ensily confuse or make mistakes. The first question: Comparison of temperature and pressure when the ideal gas went through two ways of adiabatic reversible expansion and adiabatic irreversible expansion from the same initial state to the final state with the same volume. The answer to this question can not be obtained by the maximum power principle because of the different final state,but the principle of entropy increasing was more scientific. The second question: The problem about the calculation of the rate constant and half-life of the second order reaction 2 A→B. The third question: Overheating phenomenon existed when the water distilled, how much degree was needed if the minute bubbles of a diameter was steamed out? We explained this question using Clausius-Clapeyron equation, and discussed the meaning and the value of stress of this equation.
出处
《化学教育》
北大核心
2017年第22期32-33,共2页
Chinese Journal of Chemical Education
关键词
克拉贝龙-克劳修斯方程
过热现象
速率常数
绝热可逆和绝热不可逆过程
Clausius-Clapeyron equation
overheating phenomenon
rate constant
adiabatic reversible and irreversible adiabatic process
