Experimental Scheme Design and Condition Optimization for “Substitution Reaction Between Halogen Elements”
WANG Yue-Er1, SU Lin-Ling1, CHE Lu1, WANG Zhu-Zhu1, LAN Qian1, GAO Cong-Jun2, FU Jin-Song1, ZHANG Yan-Hua1*
1. College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610068, China; 2. Panzhihua No.7 High School, Panzhihua 617005, China
Abstract In the “displacement reactions among halogen elements” experiment from the People's Education Press senior high school chemistry textbook, chlorine water is reacted with potassium iodide and potassium bromide solutions. However, hypochlorous acid in the chlorine water can also oxidize bromide ions and iodide ions, which seriously interferes with students' accurate judgment of the oxidation order of halogen elements. This study intends to adopt a water-free reaction system to eliminate the interference of hypochlorous acid in chlorine water and conduct experimental explorations on other influencing factors. The research results show that the water-free reaction system can effectively avoid the interference of hypochlorous acid, and adjusting the order of reagent addition can make the experiment more convenient and the phenomenon more obvious. This achievement provides a better experimental scheme for senior high school chemistry teaching and also makes up for the deficiencies in the experimental design in the textbook.
WANG Yue-Er, SU Lin-Ling, CHE Lu, WANG Zhu-Zhu, LAN Qian, GAO Cong-Jun, FU Jin-Song, ZHANG Yan-Hua. Experimental Scheme Design and Condition Optimization for “Substitution Reaction Between Halogen Elements”[J]. Chinese Journal of Chemical Education, 2026, 47(1): 108-113.
