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初中化学课本第21页为了讲清自燃概念——由缓慢氧化而引起自发燃烧,介绍了一个教师课堂演示实验,将白磷溶于二硫化碳,然后用滤纸浸湿后取出露置于空气中,过一会白磷在空气中缓慢氧化而到达燃点引起自燃。鉴于不少农村中学条件缺乏,市售二硫化碳不易买到,取材困难,且二硫化碳有毒性。我们设想这样改进:用甲苯代替二硫化碳,用普通卫生纸(皱纹纸)代替滤纸。实验证明,同样可收到满意的效果。方法上可取黄豆大的白磷,置于小烧杯中,加入20毫升左右的甲苯。由于常温下白磷在甲苯中溶解度不大,可将上述溶液
In order to clarify the concept of spontaneous combustion - spontaneous combustion caused by the slow oxidation, introduced a teacher classroom demonstration experiment, the white phosphorus dissolved in carbon disulfide, and then use the filter paper soaked in the air after exposure, after a White phosphorus will be slowly oxidized in the air to reach the ignition point to cause spontaneous combustion. Given the lack of conditions in many rural secondary schools, commercially available carbon disulfide is not readily available and difficult to obtain and carbon disulfide is toxic. We envisaged improvements such as replacing carbon disulfide with toluene, and replacing toilet paper with ordinary toilet paper (crepe paper). Experiments show that the same can receive satisfactory results. Method desirable soybeans large white phosphorus, placed in a small beaker, add about 20 ml of toluene. As white phosphorus at room temperature in toluene solubility is not big, the above solution