演示实验是一种最有效的直观教学方法,能帮助学生理解和掌握化学基础知识,并能给学生做出示范,有助于学生实验技能的培养。在中学化学教学中,对演示实验应加以充分重视。中学化学课程中的演示实验,多为验证性实验,一般具有装置简单、操作方便、现象明显和费时不多的特点。要做好实验,就要掌握实验的技术 Demonstration experiment is one of the most effective and intuitive teaching methods. It can help students understand and master the basic knowledge of chemistry, and can give students demonstrations and help students develop experimental skills. In chemistry teaching in middle schools, full attention should be paid to demonstration experiments. Demonstration experiments in the middle school chemistry course are mostly confirmatory experiments. Generally, they have the characteristics of simple device, convenient operation, obvious phenomena and not much time. To do experiments, we must master the experimental techniques