问题 填空题

实验室可用下列A或B装置制取氧气,用C装置收集氧气。

               

(1)写出C装置中仪器的名称:a              ,b               

(2)如果选用B、C装置制取并收集氧气,回答下列问题:

装入药品前,应先检查装置              ;试管中装入的药品是            ;当观察到C装置中                             时,开始收集氧气;实验结束停止加热时,要先                      ,然后再熄灭酒精灯。

答案

(1)a 集气瓶   ,b    水槽  。

(2)气密性    高锰酸钾  导管口的气泡连续且均匀冒出时  将导管从水槽中取出      

(1)根据实验室常见仪器和制取氧气的收集装置可知:a为 集气瓶;b为水槽;

(2)①根据实验操作步骤:①检查装置的气密性;②装药,试管固定在铁架台上;③灯加热;④收集;⑤将导管移出水面;⑥熄灭酒精灯可知:装入药品前,应先检查装置气密性;

②根据制取氧气的反应原理:用加热高锰酸钾 或 氯酸钾和二氧化锰混合物 或分解过氧化氢溶液的方法制氧,依据选用B、C装置制取并收集O2,因此试管中装入的药品是KMnO4(或KClO3和MnO2);

③根据实验操作步骤:用排水法收集氧气,集气瓶充满水后倒放入水槽中;要等到气泡连续、均匀地放出时,再开始收集,否则收集到的氧气不纯,混有空气;故答案为:导管口气泡连续地并比较均匀地冒出(或导管口有连续气泡冒出);

④根据实验操作步骤:将导管移出水面,熄灭酒精灯,故答案为:把C装置中的导管移出水面.

阅读理解

D

Mr. Frank shot well and once he had come in fourth in a competition.

Then he went to a big city on business. There he joined the local rifle club. The club had a very good team, which used to take part in a lot of important shooting competitions. One of these took place while Frank was with them. But one of the members of the club's team suddenly fell ill just before the match. The captain had heard of Mr. Frank. He therefore invited Mr. Frank to take the sick man's place.

Mr. Frank felt greatly happy to be asked to shoot for such a good team, but he also felt very nervous, because he was afraid of making a fool of himself.

In fact, he was so nervous that he could not keep his hands from trembling while he was shooting, with the result that he did very badly in the competition. When he took his score card to his captain, he said:" After seeing my score, I want to go outside and shoot myself. " The captain looked at the card for a few seconds and then said, "Well, you'd better take two bullets with you if you want to do that. "

53. Mr. Frank once__________-in a competition.

A. joined the fourth team            B. took the fourth place

C. was the fourth to start shooting     D. shot with the other three

54. Why did Mr. Frank feel nervous to be asked to shoot for the team? Because_______.

A. actually he was not good at shooting

B. he thought the captain and the other members would fool him

C. he was afraid of losing face before so many good shooters

D. he would lose a lot of money if he should fail

55. When Frank said, "After seeing my score, I want to go outside and shoot myself", he meant to say that___________

A. he wants to practice shooting all by himself

B. he wanted to find out the reason for his failure

C. he was too shamed of himself to remain inside and face the captain and the other members

D. he wanted to kill himself with the rifle

56. By saying "You had better take two bullets with you if you want to do that", the captain actually meant to say

A. "We haven't got so many bullets for you to practice shooting."

B. "You can't improve your shooting with only one bullet."

C. "I don't believe you can keep your hands from shaking this time."

D. "you are such a bad shooter that one bullet is certainly not enough to end you life with."

57. According to this passage, which of the following is wrong?

A. He fired several shots and they all missed the target.

B. The captain wasn't satisfied with Frank and laughed at him.

C. In the big city Frank was admitted to the local rifle club.

D. Frank could have done better in the competition.

单项选择题