摘要
蔗糖水解是经典的化学动力学实验之一,实验内容单调,数据处理简单。对实验方案进行了重新设计、改进,在实验体系中加入几种中性盐(NaCl、KCl、MgCl_2、CaCl_2、BaCl_2),用旋光法测定了中性盐对蔗糖水解反应速率常数及活化能的影响。结果表明,中性盐的加入对蔗糖水解反应起到动力学正盐效应,并且其阳离子所带电荷数越高,半径越小,盐效应越强。改进后的实验有助于提高学生参与实验的积极性,杜绝抄袭现象,加深学生对动力学盐效应的理解。
The acid catalyzed hydrolysis of sucrose is one of the classic chemical kinetics experiments.The experimental procedure and the data processing are simple. Measurement of optical rotation is used to determine the rate constant and activation energy when the neutral salts（ NaCl, KCl, MgCl2,CaCl2, BaCl2） are added to the sucrose hydrolysis reaction. It has been found that the neutral salts exert an accelerating influence on the reactions of sucrose hydrolysis. The positive ion with higher charge and smaller ionic radius shows stronger salt effect. The improved experiment is helpful to improve the enthusiasm of the students, to eliminate the phenomenon of plagiarism, and to deepen the understanding of the kinetic salt effect.
作者
何萍
HE Ping(Department of Chemical and Materials Engineering, Yingkou Institute of Technology, Yingkou 115000, China)
出处
《实验室科学》
2017年第6期37-40,共4页
Laboratory Science
关键词
蔗糖水解
动力学盐效应
速率常数
活化能
hydrolysis of sucrose
kinetic salt effect
rate constant
activation energy
