问题 实验题

某兴趣小组用下图装置探究氨的催化氧化

(1)氨催化氧化的化学方程式为___________________。

(2)加热玻璃管2一段时间后,挤压1中打气球鼓入空气,观察到2中物质呈红热状态;停止加热后仍能保持红热,该反应是_________反应(填“吸热”或“放热”)。

(3)为保证在装置4中观察到红棕色气体,装置3应装入_________;若取消3,在4中仅观察到大量白烟,原因是___________________。

(4)为实现氨催化氧化,也可用装置5替换装置_________(填装置代号);化合物X为_________(只写一种),Na2O2的作用是___________________。

答案

(1)4NH3+5O24NO+6H2O

(2)放热

(3)浓H2SO4;生成的NO与O2反应生成NO2,NO2与水反应生成HNO3,NH3与HNO3反应生成了

NH4NO3

(4)1;NH4Cl;与HCl反应生成氧气(合理答案均可)

单项选择题

阅读下面短文,掌握其大意,然后从16-35各题所给的A、B、C、D四个选项中,选春最佳选项。

The journey my daughter Cathy has had with her swimming is as long as it is beautiful.

Cathy suffered some terrible 16  in her early childhood. After years of regular treatment, she  17  became healthy.

Two years ago, while Cathy was watching the Olympics, a dream came into her sweet little head—to be a swimmer. Last summer, she wanted to  18  out local swim team. She practiced hard and finally  19  it. The team practice,  20  was a rough start. She coughed and choked and could hardly  21  her first few weeks. Hearing her coughing bitterly one night, I decided to  22  her from it all. But Cathy woke me up early next morning, wearing her swimsuit  23  to go! I told her she shouldn’t swim after a whole night’s coughing, but she refused to  24  and insisted she go .

From that day on, Cathy kept swimming and didn’t  25  a single practice. She had a  26  intention within herself to be the best she could be. My ten—year—old was growing and changing right before my eyes, into this 27  human being with a passion and a mission. There were moments of  28  of course: often she would be the last swimmer in the race. It was difficult for Cathy to accept that she wasn’t a  29  ---ever. But that didn’t stop her from trying.

Then came the final awards ceremony at the end of the year. Cathy didn’t expect any award but was still there to  30  her friends and praise their accomplishments. As the ceremony was nearing the end, I suddenly heard the head coach  31  , “The highest honor goes to Cathy!” Looking around, he continued, “Cathy has inspired us with her  32  and enthusiasm.  33  skills and talents bring great success, the most valuable asset(财富)one can hold is the heart.”

It was the greatest  34  of my daughter’s life. With all she hade been  35  in her ten years, this was the hour of true triumph(成功).

20()

A.however

B.therefore

C.otherwise

D.instead

单项选择题