论文部分内容阅读
一、现行教材中存在的问题我们认为北京师大编《无机化学》等教材关于三相点、凝固点的描述有些不妥,特作如下的探讨。书中对凝固点的叙述前后矛盾。含糊不清,使初学者感到无从理解。书中第二章第一节写道:“某物质凝固点(或熔点)是该物质的固相和液相蒸气压相等时的温度。这时固液两相可以长久共存。常压下水和冰在0℃时蒸气压相等(4.579mm·Hg),两相达成平衡,所以水的凝固点是0℃,当外界压力改变时,水的凝固点变化极小(见水的
I. Problems existing in current textbooks We believe that the teaching materials of Beijing Normal University’s “Inorganic Chemistry” and other textbooks are not appropriate for the description of the triple point and freezing point, and they are specially discussed as follows. The description of the freezing point in the book contradicts each other. Vagueness makes beginners unable to understand. The first section of the second chapter of the book states: “The freezing point (or melting point) of a substance is the temperature at which the solid and liquid vapour pressures of the substance are equal. At this time, the solid and liquid phases can coexist for long periods of time. At 0°C, the vapor pressure is equal (4.579mm·Hg) and the two phases reach equilibrium. Therefore, the freezing point of water is 0°C. When the external pressure changes, the freezing point of water changes very little (see the water’s