一种含氢燃料火焰降温观色筒的设计和应用*

针对酒精灯火焰呈黄色的解释争议进行研究,以降低环境温度和减少氧气浓度为方向,设计了可观察环境温度变化对含氢燃料火焰颜色影响的仪器。对乙醇、丁烷、蜡烛等燃烧火焰进行降温测试,发现含氢燃料正常燃烧火焰颜色一般为黄色、降低环境温度后变为极淡的蓝色(光亮条件下)的规律,证明了燃烧过程中水分子处于激发态是导致火焰颜色由蓝色变为黄色的重要原因,钠元素的焰色反应不是酒精灯火焰呈黄色的唯一原因。对丁烷喷枪火焰颜色的降温测试,意外观察到4种疑似氢原子光谱的可见光谱线,为今后寻找该谱线提供了可借鉴的方向。研究过程可作为基于真实情境的研究素材,通过问题的发现、仪器的改进和规律的总结,提高学生运用化学知识解决真实问题的能力,培养学生的核心素养。

Design and Application of a Color Tube for Hydrogen Fuel Flame Cooling

In order to reduce the ambient temperature and oxygen concentration, an instrument was designed to observe the effect of ambient temperature change on the flame color of hydrogen fuel. It was found that the flame color of hydrogen containing fuel was generally yellow, and it turned to very light blue(under bright conditions) after reducing the ambient temperature. It was proved that the excited state of water molecules in the combustion process was the important reason for the change of flame color from blue to yellow. The flame color reaction of sodium element was not the only reason for the yellow flame of alcohol lamp. Four kinds of visible spectral lines of hydrogen atom spectrum were observed by accident during the temperature reduction test of flame color of butane spray gun, which provided a reference direction for the future search of this spectral line. The research process can be used as the research material based on the real situation. Through the discovery of problems, the improvement of instruments and the summary of laws, the ability of students to solve real problems by using chemical knowledge can be improved, and the core literacy of students can be cultivated.