题干

2SO2(g)+O2(g)═2SO3(g)反应过程的能量变化如图所示.已知1mol SO2(g)氧化为1mol SO3(g)的△H=﹣99kJ•mol1.请回答下列问题:

图中A表示 ____,E的大小对该反应的反应热 ____(填“有”或“无”)影响.该反应通常用V2O5作催化剂,加V2O5会使图中B点 ____(填“升高”还是“降低”),△H ____(填“变大”、“变小”或“不变”).图中△H= ____ kJ•mol1

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答案(点此获取答案解析)

反应物总能量,无,降低,不变,﹣198

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同类题5

阅读说明文《黑匣子》,完成后面的题。
                                                                                               黑匣子
      马航MH-370航班失去联系很多天了,各国救援船只现在都在客机可能坠落的海域进行搜索,但马航波音777客机仍杳无音讯。马航航班失联事件,再次成为一个“史无前例的”事件,这一事件表明全球航空业的数据通信、数据备份实在太落伍。业者建议,黑匣子的数据,应该实时传回地面,这样无需在出现事故之后投入巨大人力物力进行寻找。
      所谓黑匣子,就是一种飞行数据记录仪。黑匣子的外壳坚实,为长方体,约等于四、五块砖头垒在一起一般大。黑匣子被漆成明亮的桔红色,这种明亮显眼的颜色,以及记录仪外部的反射条件,都使得事故调查员们可以在飞机失事后很快地找到记录仪,特别是当飞机坠落在水上时。为了承受飞机坠毁时的猛烈撞击和高温烈焰,黑匣子的外壳具有很厚的钢板和许多层耐热防冲击保护材料。根据欧洲的标准,黑匣子必须能够抵受2.25吨的撞击力,在1100℃高温下10小时仍不会受损。即便飞机已完全损坏,黑匣子里的记录数据也能完好保存。
    “黑匣子”是一位墨尔本工程师在1958年发明的。1908年,美国发生了第一起军用飞机事故。此后,随着飞行事故不断发生,需要有一种追忆事故发生过程原因的仪器。二战期间,飞行记录装备仪器在军用飞机上应用,后来又用到民航飞机上。飞行记录仪之所以被称为“黑匣子”可追溯到1954年,当时飞机内所有的电子仪器都是放置在大小、形状都统一的黑色方盒里。
      大多数的飞机上安装的黑匣子有两种。一是称为飞机数据记录器的黑匣子,专门记录飞行中的各种数据,如飞行的时间、速度、高度、飞机舵面的偏度、发动机的转速、温度等,共有30多种数据,并可累计记录25小时。起飞前,只要打开黑匣子的开关,飞行时上述的种种数据都将收入黑匣子内。一旦出现空难,整个事故过程中的飞行参数就能从黑匣子中找到,人们便可知道飞机失事的原因。另一种称为飞行员语言记录器的黑匣子,就像录音机一样,它通过安放在驾驶舱及座舱内的扬声器,录下飞行员与飞行员之间以及座舱内乘客、劫机者与空中小姐的讲话声,它记录的时间约为2个小时,录完后,会自动倒带从头录起,若发生空难,之前的两个小时会被完整保留,并持续发出讯号,直到断电为止。