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课上,同学们探究了“固体熔化时温度的变化规律”。老师给每个学习小组提供的固体是一种不太常见的化学药品——海波(硫代硫酸钠)。当把装有海波的试管放在盛有热水的大烧杯里后,搅动试管内的玻璃棒,并随时观察温度计,每半分钟记录一次温度。观察到的实验现象是:开始加热时,海波物态不变,温度计示数逐渐增大;在一定的温度下(熔点)海波开始融化,熔化过程中吸热,但温度计示数保持不变,海波处于固液共存态;当海波全部熔化完毕,继续加热,温度计示数又逐渐增高。
In the class, the students explored the “change in temperature of the solid when melting”. The solid that the teacher provided to each study group was a less common chemical - Hypo (sodium thiosulfate). When the test tube containing the sea wave is placed in a large beaker containing hot water, the glass rod in the test tube is agitated, and the thermometer is observed at any time, and the temperature is recorded every half minute. The observed experimental phenomenon is that when the heating is started, the state of the sea wave does not change, and the number of thermometers gradually increases; the sea wave begins to melt at a certain temperature (melting point), and heat is absorbed during melting, but the number of thermometers is not maintained. Change, the sea wave in the solid-liquid coexistence state; when the sea wave is completely melted, continue to heat, the thermometer shows a gradual increase.