0  300160  300168  300174  300178  300184  300186  300190  300196  300198  300204  300210  300214  300216  300220  300226  300228  300234  300238  300240  300244  300246  300250  300252  300254  300255  300256  300258  300259  300260  300262  300264  300268  300270  300274  300276  300280  300286  300288  300294  300298  300300  300304  300310  300316  300318  300324  300328  300330  300336  300340  300346  300354  447090 

4.2001年11月,美军向躲藏在山洞中的阿富汗恐怖分子使用了一种名为BLU-82的燃料炸弹,这种炸弹爆炸能耗尽山洞中的氧气,使洞中的生物窒息死亡。该炸弹的主装药是环氧乙烷(化学式为C2H4O)。关于环氧乙烷的下列说法正确的是(   )   

  A、它是氧化物         B、它是含有3种元素的混合物

  C、它的摩尔质量是44g      D、1 mol环氧乙烷含有2NA个碳原子

试题详情

3.将下列各组物质按单质、氧化物、酸、碱、盐分类顺序排列,其中正确的是(  )

A、水银、干冰、硫酸、烧碱、食盐

B、碘酒、冰、盐酸、火碱、食盐

C、氢气、二氧化硫、硝酸、纯碱、胆矾

D、铜、氧化铜、醋酸、石灰水、氯化铜

试题详情

2.下列各组内物质的转化,只通过一步反应不能完成的是(   )

A、Zn→H2   B、KMnO4→MnO2   C、CO2→CaCO3     D、Cu→Cu(OH)2

试题详情

1.在我们的日常生活中出现了“加碘食盐”、“增铁酱油”、“高钙牛奶”、“富硒茶叶”、“含氟牙膏”等商品。这里的碘、铁、钙、硒、氟,应理解为(   )

A、单质      B、分子      C、元素      D、氧化物

试题详情

I was cleaning out an old box when an old card caught my eye : Queen City Casket Company . “What is it ?” I wondered . I  36    it over . There , in faded ink , was a hand-scrawled(手写的)  37    . Immediately my mind traveled   38   many years .

I was nine years old , walking down the cold , wet streets of Springfield , with a bag of magazines on my shoulder . On my   39    that day , I came to that Company finally , whose owner , Mr Rader , had always taken me there to ask his workers   40    they wanted any magazines .

Shaking off the   41   like a wet dog , I entered Mr Rader’s office . After a quick glance he   42   me over to the fire-place . Noticing the   43   in the top of my   44   , he said , “ Come with me !” pulling me into his pickup   45    . We pulled to a stop before a shoe store . Inside , a salesman   46    me with the finest pair of Oxfords I had   47    seen . I   48   about 10 feet tall when I got up   49    them . “ We’d like a pair of new socks too,” Mr Rader said .

Back in his office , Mr Rader took out a   50   , wrote something on it , and handed it to me . With   51    eyes , I read , “ Do to others as you would have them do to you .” He said affectionately (深情地), “Jimmy , I want you to   52    I love you”.

I said good-bye , and for the first time I   53    a flicker of hope that somehow things would be   54    . With people like Mr Rader in the world , there was hope , kindness and love , and that would always make a   55    .

36.A.read               B.thought            C.turned          D.passed

37.A.address            B.list              C.message           D.information

38.A.forward            B.so              C.ahead         D.back

39.A.return          B.rounds          C.trip             D.arrival

40.A.if only          B.how               C.whether            D.why

41.A.dust               B.sweat           C.tail             D.rain

42.A.led             B.followed            C.watched           D.carried

43.A.hole               B.mud               C.water          D.cover

44.A.magazine       B.shoe            C.sock            D.bag

45.A.truck           B.factory          C.home          D.store

46.A.dressed             B.fitted           C.showed            D.comforted

47.A.ever               B.already            C.never          D.hardly

48.A.appeared          B.seemed            C.looked         D.felt

49.A.for             B.with                C.on             D.in

50.A.pen               B.paper          C.card               D.notebook

51.A.tearful          B.unbelievable        C.curious         D.puzzled

52.A.admit          B.know           C.consider            D.express

53.A.sensed         B.received            C.lost             D.gained

54.A.mistaken           B.right            C.all right         D.possible

55.A.deal               B.fortune          C.choice         D.difference

试题详情

6、工业制纯碱时,第一步是通过饱和食盐水、氨和二氧化碳反应,获得碳酸

氢钠结晶,它的反应原理可以用下面方程式表示:NH3+CO2+H2O    NH4HCO3,NH4HCO3+NaCl(饱和)   NaHCO3↓+NH4Cl

以上反应总结果是放热反应。请设计一个实验,用最简单的实验装置模拟实现这一过

程,获得NaHCO3结晶。

   可供选择的实验用品有:6mol/L-1盐酸、6mol/L-1的硫酸、浓氨水、氢氧化钠、石灰石、氯化铵、食盐、蒸馏水、冰、以及中学化学常用仪器。

   (1)画出实验装置示意图(包括反应时容器中的物质),并在图中玻璃容器旁自左至右分别用A、B、C……符号说明。

   说明①本题装置示意图中的仪器可以用下面的方式表示

图4-7

   ②铁架台、石棉网、酒精灯、玻璃导管之间的联接胶管等,在示意图中不必画出。如需加热,在加热的仪器下方,标出“△”表示。

   (2)请写出在图4-7上用A、B、C……各玻璃容器中盛放物质的化学式或名称。

   A:      B:      C:       D:      

   (3)利用本题所提供的实验用品,如何判断得到的产品是碳酸氢钠的结晶,而不是碳酸氢铵或食盐结晶。

   答:                        

试题详情


同步练习册答案