燃烧热测定实验的改进

Improvement in Combustion Heat Determination

目的燃烧热测定实验是物理化学中一个十分经典的教学实验,针对燃烧热测定实验中存在的实验成功率低,实验时间长的缺点进行了三点实验技术改进.方法根据点火丝特性控制点火电流强度,将传统的直燃式点火方式改进为助燃式点火方式,同时增加苯甲酸与萘的使用量.结合以上三点实验技术改进对萘的燃烧热进行测定并计算相当误差.结果萘的燃烧热测量相对误差为1.9%,点火成功率由72%左右提高到95%以上,实验时间由平均7小时缩短到平均4小时.结论通过对燃烧热测定实验进行实验技术改进,达到了萘燃烧热测量相对误差小于5%的教学实验要求,提高了该实验的可操作性,证明对该实验进行的实验技术改进是成功和合理的.

Objective Combustion heat determination is a very classic teaching experiment in physical chemistry. To solve the problem of the low success rate and long experimental time, three improved experimental technologies were brought up. Methods By controlling the electrical current pore fire, changing the method of port fire from direct to indirect, and increasing the use of drugs with benzoic acid and naphthalene. Results The inaccuracy of naphthalene＇s combustion heat was about 1.9%, the success rate was improved from 72% to 95%, and the time for this experiment declined from 7h to 4h. Conclusion To improve combustion heat determination, the experimental inaccuracy is lower than 5 %, the demand of physical chemistry experiment. The operability for this experiment has been improved. It proves that the improvement is successful and reasonable.