题目

The Sound of Music is one of the most.popular American movies.It is a story about a young woman,living in Austria.Her name was Maria.She went to the Van Trapp family to care for seven children. Mrs. Von Trapp died,and the family were very sad and tired.The children cried and shouted every day:The father was lonely and often became angry because of the noisy children. Maria taught the children to sing lively songs and perform short,funny plays to cheer themselves up.The father was almost mad at first,but the smiling faces of his children pleased him and made him happy (6分)元旦联欢会上,化学老师给同学们表演了一个“水能生火”的魔术(如图所示),他将包有过氧化钠(Na2O2)粉末的脱脂棉放在石棉网上,向棉花上滴了几滴水,棉花立刻燃烧了起来。同学们产生了浓厚的兴趣,为什么脱脂棉会燃烧起来呢?【提出猜想】a.小明认为过氧化钠(Na2O2)与水反应生成了可以支持燃烧的物质。b.小刚又根据燃烧的条件,对小明的猜想进行了补充: 。【实验与分析】同学们设计了图的实验装置。(1)打开分液漏斗的活塞,控制水滴加的速度,看到试管中有气泡产生,将带火星的木条靠近P出口,看到木条复燃,你推测此气体可能是 。(2)实验中还观察到,烧杯中的导气管口有气泡冒出,产生这一现象的原因是 。(3)完成了以上实验,老师介绍该反应的产物一共有两种,于是同学们又展开了进一步的研究,继续探究反应后生成的另一种物质。请你回答:另一种产物必含的元素是_______________。【老师介绍】 过氧化钠不仅可以和水发生反应,也可以和二氧化碳反应,也能生成氧气。因此,过氧化钠经常被用于潜水艇和防毒面具中提供氧气。【补充实验】明确了以上性质,小芳同学又设计了一个实验(如图):将一团包有过氧化钠的粉末的棉花塞到漏斗的管中,漏斗下方点燃一支短蜡烛 (蜡烛火焰与棉花不接触)。请回答:棉花 (填“能”或“不能”)燃烧。这主要是因为蜡烛燃烧生成能与过氧化钠(Na2O2)反应的物质___________________,同时反应放热。
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