人民教育出版社化学室编著的九年义务教育初中《化学》教科书中的课堂演示实验［实验5－6］，有如下不足：（1）如果烧杯内蜡烛点燃时间过长，因放出的热量多，易导致集气瓶中的CO2不能全部倒入烧杯中（部分CO2被热流赶跑），CO2盛入瓶底就更加困难，常造成烧杯底部的蜡烛出现 Nine-year compulsory education edited by the People’s Education Press Chemistry Room The classroom demonstration experiment in the “Chemistry” textbook for junior high school [Experiment 5-6] has the following deficiencies: (1) If the candles in a beaker are lighted for too long, the amount of heat released is excessive. , It is easy to cause the CO2 in the gas cylinder not to be completely poured into the beaker (some CO2 is run away by heat), and it is more difficult for the CO2 to fill the bottom of the bottle, often causing the candle at the bottom of the beaker to appear