“拉环法测定液体表面张力”实验讨论

Discussion on the Experiment "Measuration of Surface Tension by Ring-Pulling Method"

在物理化学实验中,液体表面张力的测定是必修的实验之一,特别是表面张力仪法测定液体的表面张力。文章对"拉环法测定液体表面张力"这一实验的原理进行阐述分析。经过实验教学中的观察实践,指出了学生容易在液体表面张力值的确定上产生疑问。文中正是针对这个疑问,结合电压随时间的变化图和吊环所受液体表面张力示意图进行分析讨论,给出了详细的解释,为学生答疑解惑。

In physical chemistry experiments,liquid surface tension is one of the compulsory test,particularly,mensuration of surface tension by surface tension instument method.In the paper,the principle of experiment ＂measuration of surface tension by ring-pulling method was explained＂.Through experimental observation in teaching practice,we found that the puzzling question about the value of surface tension ordinarily raised by many undergraduates.In order to rid the puzzles for them,we interpretate the question in details combined with the figure of voltage-time and the surface tension suffered by the ring.