问题 完形填空
完形填空。
     The United States is full of automobiles (机动车). There are still many families without cars. But some
families have two or  1  more cars. However, cars are used for more than pleasure. They are a  2  part of life.
     Cars are used for  3 . They are driven to offices and factories by workers who have no other way to  4  
their jobs. When salesmen are sent to  5  parts of the city, they have to drive in order to  6  their products.
Farmers have to drive into the city in order to shop for necessities.
     Sometimes, small children must be driven to  7 . In some cities, school buses are used only when children
  8  more than a mile from the school. When the children are too  9  to walk that far, their parents take  10 
 driving them to school. One  11  drives on Mondays, taking her children and the neighbors' children as well.
Another mother drives on Tuesdays, another on Wednesdays and so on. This is  12  forming a car pool (拼车).
Working people also form car pools, with three or four people taking turns driving to the place  13  they work.
     More car pools should be formed in order to put  14  cars on the road and to use less oil.  15  is a great
problem, and so is the traffic in and around cities. Too many cars are being driven. Something should be done
about the use of cars.
( )1. A. even    
( )2. A. great   
( )3. A. families
( )4. A. get to  
( )5. A. same    
( )6. A. catch   
( )7. A. cities  
( )8. A. move   
( )9. A. small   
( )10. A. money  
( )11. A. parent  
( )12. A. call   
( )13. A. where  
( )14. A. more   
( )15. A. Driving
B. much       
B. necessary  
B. business  
B. look for  
B. different  
B. create    
B. schools    
B. study      
B. big        
B. time      
B. child      
B. calling   
B. that      
B. fewer      
B. Running    
C. little    
C. proper    
C. education 
C. find out  
C. every     
C. cover     
C. parks     
C. live     
C. young    
C. pride     
C. way       
C. to call   
C. which     
C. many     
C. Parking   
D. such    
D. possible
D. farms   
D. use up  
D. each    
D. carry   
D. gardens 
D. work    
D. old     
D. turns   
D. car                             
D. called  
D. when    
D. less    
D. Forming 
答案

1-5     ABBAB     6-10    DBCCD     11-15   ADABC

填空题

合成氨对农业生产及国防建设均具有重要意义。

N2(g)+3H2(g)  2NH3(g) △H = -92 kJ·mol-1

(1)在恒温恒容密闭容器中进行的合成氨反应,下列能表示达到平衡状态的是_______

a.混合气体的压强不再发生变化

b.混合气体的密度不再发生变化

c.反应容器中N2、NH3的物质的量的比值不再发生变化

d.单位时间内断开a个H-H键的同时形成3 a个N-H键

e.三种物质的浓度比恰好等于化学方程式中各物质的化学计量数之比

(2)在恒温恒容的密闭容器中,合成氨反应的各物质浓度变化曲线如下图所示。请回答下列问题:

① 表示N2的浓度变化的曲线是              (选填曲线代号“A”、“B”或“C”)。

② 前25 min 内,用H2的浓度变化表示的化学反应平均速率是               

③在25 min 末反应刚好达到平衡,则该温度下反应的平衡常数K =           (计算结果可用分数表示)。若升高温度,该反应的平衡常数值将___  ____(填“增大”、“减小”或“不变”)。

(3)在第25 min 末,保持其它条件不变,若升高反应温度并设法保持该温度不变,在第35 min末再次达到平衡。平衡移动过程中H2浓度变化了1.5 mol·L-1,请你在图中画出第25 min ~ 40 min NH3浓度变化曲线。

(4)在一定温度下,将1 mol N2和3 mol H2混合置于体积不变的密闭容器中发生反应,达到平衡状态时,测得气体总物质的量为2.8 mol 。

①达平衡时,H2的转化率α1 = ______  ______。

②在相同条件下,若起始时只将NH3置于该容器中,达到平衡状态时NH3的转化率为α2,当α1 + α2 =1时,则起始时n (NH3)= ___  _____mol。

填空题