问题 填空题

比较与归纳,是我们学习化学的常用方法。请结合下列实验常用装置,回答有关问题。

A                   B          C         D          E

(1)      写出图中带有标号仪器的名称:a          ,b             

(2)用高锰酸钾制取并收集氧气时,应选用的发生装置是      (填序号,下同),某同学用排水法收集氧气时发现水槽中的水变红了,请你帮他分析可能的原因是                       ;排水法收集满一瓶气体后应如何操作                                                       ;高锰酸钾分解制氧气的化学方程式为                                    

(3) 实验室还可用二氧化锰和双氧水来制取氧气 ,二氧化锰在该反应中起        作用。应选用的发生装置是     ,用该发生装置制取气体应满足的一般条件是                    ,收集装置是      ,用该收集装置收集气体应满足的一般条件是                    。其反应方程式是                      

(4)归纳、总结和预习是学习化学重要的方法,小明对接下来学习二氧化碳的制取充满期待,经查阅资料后了解到实验室可用石灰石或大理石,【主要成分是碳酸钙固体(CaCO3)】和稀盐酸(HCl)在常温下反应制取制二氧化碳,同时生成氯化钙(CaCl2)和水,该反应方程式为                                ;且二氧化碳可溶于水,密度比空气大。请你根据所学知识帮其判断制取二氧化碳应选用的发生装置和收集装置分别为                   

答案

(1)a、试管    b、酒精灯

(2)A    先将导气管从水中拿出,然后再停止加热

(3)催化  B  固体和液体反应无需加热  C或E  密度比空气大或不易溶于水

  

(4)CaCO3 + 2HCl=CaCl2 + H2O + CO2↑    B    C

(1)试管、酒精灯是初中化学常见的仪器,故a:试管  b:酒精灯;

(2)高锰酸钾制取氧气,发生装置应选择固体加热制气装置,故选A;水槽里的水变红说明装置A试管口处没有放置棉花团,高锰酸钾粉末被气流吹入水中;排水法收集满一瓶氧气后应先将导气管从水中拿出,然后再停止加热,以免水倒流使试管炸裂;高锰酸钾制氧气的化学方程式为

(3)实验室用双氧水和二氧化锰制取氧气,二氧化锰起催化作用;发生装置应选择装置B——固液制气装置,该发生装置制取气体应满足于反应物为固体和液体,反应条件常温下就可以进行;收集装置C或装置E,可收密度大于空气或不易溶于水且不水反应的气体;反应的化学方程式为

(4)大理石的主要成分为碳酸钙,与稀盐酸反应生成氯钙、水和二氧化碳,故化学方程式为CaCO3 + 2HCl=CaCl2 + H2O + CO2↑,反应物为固体与液体,常温下进行,故发生装置为B装置;二氧化碳可溶于水,密度比空气大,故可以选择向上排空气法收集,收集装置为C。

阅读理解

阅读理解。

     Little Tommy was doing very badly in math. His parents had tried everything-tutors, cards, special

learning centers-in short, everything they could think of. Finally they took Tommy to a catholic (天主教的)

school.

     After the first day, little Tommy came home with a very serious look on his face. He didn't kiss his

mother hello. Instead,he went straight to his room and started studying. Books and papers were spread

(铺开) out all over the room and little Tommy was hard at work. His mother was surprised. She called

him down to dinner and as soon as he finished eating, he went back to his room, without a word. In no

time he was back hitting the books as hard as before. This went on for some time, day after day while

the mother tried to understand what was happening. 

     Finally,little Tommy brought home his report card. He quietly put it on the table and went up to his

room and hit the books. His mom looked at it and to her surprise, little Tommy got an A in math. She

could no longer hold her curiosity (好奇心). She went to his room and asked, "Son, what was it? Was it

the nuns (修女)?"

     Little Tommy looked at her and shook his head, "No."

     "Well then," she asked again. "WHAT was it?"

     Little Tommy looked at her and said, "Well, on the first day of school, when I saw that man nailed

(钉) to the plus sign (加号), I knew they weren't joking."

1. Why did Tommy's parents send him to a catholic school? [ ]

A. Because he could eat well there.

B. Because his parents could save some money.

C. Because his parents wanted him to do better in his math.

D. Because his parents didn't want him to learn math any more.

2. Tommy's mother felt surprised that his son ______. [ ]

A. was still the same as usual

B. ate so much at dinner

C. kissed her hello after school

D. worked hard but said little

3. "Hitting the books" means "______" in Chinese. [ ]

A. 用功

B. 捶书

C. 发泄

D. 振作

4. The last sentence in the passage shows that ______. [ ]

A. Tommy felt sorry for the mail

B. Tommy was afraid of being nailed

C. Tommy didn't like the plus sign

D. Tommy liked playing jokes on others

5. From the passage,we can infer (推断) that ______. [ ]

A. teachers should be strict with their students

B. mistaking (误解) might be good things sometimes

C. a catholic school is much better than other ones

D. nuns are good at helping children with their math

单项选择题