摘要
针对“凝固点降低法测萘摩尔质量”实验中萘一苯溶液过冷温度很难找准的问题，进行了反复实验，结果表明：纯苯的凝固点温度为5．4℃，与教材一致。25mL苯中分别加1．0、1．1、1．2、1．3、1．4、1．5g萘溶液进行过冷，则最低温度为4．91～4．69℃，呈依次下降势态；回升最高温度在5．30～4．93℃之间，过冷温差为0．37～0．24℃。通过控制加冰量和速度的方法控制过冷温度，以每分钟降低0．2℃比较合适，所测萘的摩尔质量为117．62g·mol^-1，与标准值相比误差为-8．23％。该实验条件为在有限的时间内达到良好的实验效果提供了参考。
In the experiment of measuring naphtha line molar mass by using the method of reducing freezing point, the super-cooling temperature of naphtha line-benzene liquor can not be found out, so the experiment was repeatedly done. The result shows that the freezing point temperature of pure-benzene is 5.4 ℃ in accordance with teaching materials. A decreasing trend was found in the temperatures when 25mL benzene was added separately 1.0,1. 1,1. 2,1. 3,1. 4,1. 5 g into naphtha line liquor, and the lowest super-cooling temperatures were 4.91 to 4.69 ℃. The highest return temperatures were between 5.30 and 4.93 ℃ and the differences in super-cooling temperature were between 0.37 and 0.24 ℃, It is more appropriate and easy to observe by controlling ice volume and speed to control super-cooling temperature decreased 0.2 ℃ per minute. The measured molar mass is 117.62 g . mol^-1. Compared with the standard value, the error is -8. 23%. According to the data of this experiment, it is beneficial to achieving the ideal experiment results in the limited time.
出处
《实验技术与管理》
CAS
北大核心
2009年第4期23-25,共3页
Experimental Technology and Management
基金
江苏省“十一五”高等教育科学研究规划课题(JS161)
南京信息工程大学教改基金
关键词
凝固点
萘-苯溶液
过冷温度
freezing point
naphtha line-benzene liquor
super-cooling temperature
