用燃烧硫所发生的 SO_2来演示 SO_2的漂白作用,从教学效果上讲,比用其他来源的 SO_2要恰当些。但它的缺点是要经过较长的时间,才能见到明显的结果。建议改用富氧空气代替空气,以缩短演示实验的时间。课前准备:取1—2升的细口瓶一个,瓶内挂一束润湿的鲜花,再通入氧气约1/3体积,用橡塞塞好后带进教室。演示手续:在燃烧匙内放硫1—2克,点着后伸入瓶内,硫就迅速烧完,因为瓶内的 SO_2的浓度较大,温度又较高,因此,鲜花就很快地被漂白。若用中学课本的装置,那末可用具有塞子的钟罩, The combustion of sulfur SO2 to demonstrate the SO2 bleaching effect, from the teaching effect, than with other sources of SO2 to be more appropriate. But its downside is that it takes a long time to see obvious results. It is recommended to use oxygen-enriched air instead of air to shorten the time for demonstration experiments. Pre-class preparation: take a 1-2 liter bottle, a bottle of wet flowers hanging, and then into the oxygen about 1/3 of the volume, with the rubber stopper into the classroom. Demonstration: Sulfur spoon in the burning 1-2 grams, after the point into the bottle, the sulfur burned quickly, because the bottle of SO 2 concentration, the temperature is higher, so the flowers quickly Bleached. If you use a secondary school textbook device, then use a bell with a stopper,