问题 填空题

实验室通常采用下图所示的两套装置,用不同的方法来制取氧气.

(1)A、B装置中收集气体的方法叫作______;试管口应略向下倾斜的原因是:______.

(2)某同学用A装置制取并收集一瓶氧气,试管中所放化学药品是高锰酸钾,发生反应的化学表达式为:______;

装置中还缺少______;作用是为了防止______,可以采用图中集气法收集氧气的原因是______.

若不改进A装置来制取氧气,可以用另外的药品,写出反应的化学表达式:

______;属于______反应(填反应类型).

(3)若采用B装置制取氧气,在分液漏斗中应盛放的液体药品是______(填化学式),锥形瓶底部放入的固体药品是______(填化学式),反应的化学表达式为______;B装置中采用分液漏斗的优点是(只要求写出一点):______.

(4)实验室用高锰酸钾制取氧气,有下列操作步骤①点燃酒精灯,给试管加热②检查装置的气密性③装入药品,连接仪器并固定装置④用排水法收集气体⑤从水槽中取出导管⑥熄灭酒精灯⑦连接仪器,正确的操作顺序是______.

A、⑦②③①④⑤⑥B、①⑦③②⑤④⑥

C、⑤⑦③②①④⑥D、⑦③①②④⑥⑤

(5)在常温下,用亚硫酸钠固体和稀硫酸制取二氧化硫气体,应选用的发生装置是______;(填序号)由于二氧化硫是易溶于水、密度比空气大的有毒气体,所以应选用______装置进行收集,以便将尾气吸收处理,避免造成大气污染.

答案

(1)观察图示可知是排水法收集气体;防止产生的冷凝水倒流入试管底部,使试管受热不均而炸裂,要让试管口向下倾斜.故答案为:排水集气法、防止产生的冷凝水倒流入试管底部,使试管受热不均而炸裂;

(2)跟据反应物是高锰酸钾,反应条件是加热,可知化学反应式是:2KMnO4

  △  
.
 
K2MnO4+MnO2+O2↑;图中试管口还缺少防止高锰酸钾进入导气管的一团棉花;因为氧气不易溶于水,我们可用排水法收集.也可用装置A加热氯酸钾和二氧化锰的混合物制取氧气;反应化学式是:2KClO3
MnO2
.
2KCl+3O2;此反应是一种物质生成两种或两种以上其他物质的分解反应.

故答案为:2KMnO4

  △  
.
 
K2MnO4+MnO2+O2↑、一团棉花、加热时高锰酸钾进入导气管,阻塞导气管、氧气难溶于水、2KClO3
MnO2
.
2KCl+3O2、分解;

(3)用B装置制取氧气,要用到的药品有固体二氧化锰,液体过氧化氢,分液漏斗中盛放过氧化氢(H2O2),锥形瓶中放二氧化锰(MnO2);反应的化学式是:2H2O2

 MnO2 
.
 
2H2O+O2↑;分液漏斗可控制过氧化氢液体滴加的速度,使反应随开随停.故答案为:H2O2、MnO2、2H2O2
 MnO2 
.
 
2H2O+O2↑、可以控制滴加液体的速度;

(4)记住氧气的操作步骤口诀“查装定点收移熄”,谐音“茶庄定点收利(离)息”;依次对号入座,找出关键字.步骤是:⑦②③①④⑤⑥.故答案为:⑦②③①④⑤⑥;

(5)制取二氧化硫气体,用亚硫酸钠固体和稀硫酸在常温下反应,所以我们选用装置B制取;又因为二氧化硫是易溶于水、密度比空气大的有毒气体,我们应选取装置E作为收集装置.故答案为:B、E.

阅读理解

The other day in school, we were discussing jobs. Our teacher, Mrs. Bolt said that career was very important and that it was never too early to think about your life’s work. Most of the young boys really were not too sure about what they wanted to be. But I knew exactly what I wanted to be, and when Mrs. Bolt asked me, I replied “A truck driver.”

“A truck driver?” repeated Mrs. Blot. “Why do you want to be one, Tom?”

“Because truck drivers are always on the move. They do not have to sit at desks all day. They are out on the road and they see a lot of the country. The pay is good, too. And you never have any homework.”

The class laughed.

“Well, Tom.” answered Mrs. Bolt. “You certainly sound quite enthusiastic (热情的). I guess that you don’t like sitting at a desk or doing homework. Is that correct, Tom?”

“Yes, I guess so, ” I said.

“Well, since you are so interested in becoming a truck driver, I think you should look into the field a little further. I want you to go to the library and take out a book on truck driving. And I want you to write a paper on it and hand it in at the end of the month.”

That’s the last time I’ll never tell anybody my secret ambition (雄心).

46.Mrs. Bolt suggested Tom write a book report because         .

A.she was angry with him.

B.she wanted him to learn about the other side of truck driving.

C.she was making fun of him.

D.she wanted the whole class to follow him

47.Which of the following is NOT true?

A.The writer thinks that truck drivers are well paid.

B.What Tom said made his classmates laugh.

C.It seemed as if Tom did not enjoy doing his homework.

D.Mrs. Bolt didn’t want Tom to become a truck driver.

48.Tom wouldn’t tell about his ambition any more because          .

A.he didn’t think his ambition could come true.

B.he just got more homework to do.

C.he was laughed at by the whole class.

D.he would not be able to become a truck driver.

49.What can we infer about Mrs. Bolt?

A.She was unkind to her students.            B.She was unfit for her position.

C.She was a teacher with ripe experience.  D.She always did something strange. 

问答题 简答题