在初中化学第二章第二节《氢气的性质和用途》和第五节《离子化合物和共价化合物》的教学中,教师要做氢气在氯气中燃烧和钠在氯气中燃烧的演示实验。按书上的仪器装置实验时,教师需事先制取氯气。教师在制取氯气的过程中以及在做上述实验时,都会有一定量的氯气扩散到实验室或教 In the teaching of junior high school chemistry, the second chapter, “Hydrogen properties and uses” and the fifth section “Ionic compounds and covalent compounds”, the teacher to do the demonstration experiment of hydrogen burning in chlorine and sodium burning in chlorine. According to the instrument setup of the book, the teacher must prepare chlorine in advance. Teachers in the process of making chlorine and when doing the above experiments will have a certain amount of chlorine gas diffused into the laboratory or taught