问题 问答题

小红同学用加热高锰酸钾的方法,实验装置示意图如图1

回答下列问题:

(1)写出下列序号仪器的名称:

①______,②______,③______.

(2)实验室用高锰酸钾制取氧气反应的化学方程式为:______.

(3)实验室制取氧气的主要操作步骤有①从水槽中取出导管   ②检验装置的气密性

③停止加热  ④收集气体  ⑤加热  ⑥加入药品,请写出正确的操作顺序(填序号):______.

(4)小红做该实验出现了下列异常现象,请你分析其原因:

现象原因
水槽中水呈紫红色
水被倒吸沿导管进入试管中
(5)检验装置气密性的操作如下(如图2所示):

先将导管伸入液面下,用手紧握试管,观察到______,松开手后,导管口内有液面上升.

(6)小刚同学认为用过氧化氢分解的方法制取氧气更为方便,其反应的化学方程式为:______该方法用到的二氧化锰的作用是______.

答案

(1)试管常用的反应容器,酒精灯是常用的加热仪器,铁架台是夹持仪器,故答案为:试管;酒精灯;铁架台

(2)高锰酸钾在加热的条件下生成锰酸钾和二氧化锰和氧气,配平即可;故答案为:2KMnO4

  △  
.
 
K2MnO4+MnO2+O2

(3)实验室用高锰酸钾制取氧气的主要操作步骤是:检验装置的气密性;加入药品;加热;收集气体;从水槽中取出导管;停止加热.故答案为:②⑥⑤④①③

(4)如果用高锰酸钾制氧气就需要加热,试管口要放一团棉花,防止高锰酸钾粉末进入导管;先熄灭了酒精灯,后移出导管,水被倒吸沿导管进入试管中,试管会炸裂,故答案为:试管口要放一团棉花;先熄灭了酒精灯,后移出导管

(5)检查装置气密性的方法是:先把导管的一端插入水中,然后两手紧握试管的外壁,如果导管口有气泡冒出,证明装置严密,松开手后,过一会导管口内有液面上升;故答案为:有气泡冒出

(6)过氧化氢在二氧化锰做催化剂的条件下生成水和氧气,其中二氧化锰起催化作用,故答案为:2H2O2

MnO2
.
2H2O+O2↑;催化作用

阅读理解

I have a painfully vivid memory of my first homecoming from college, in December 1983. After three whole months away, I was back home with my brand new opinions, attitudes and tastes. How could they watch such terrible television programs? I, the English Literature major with Shakespeare and Milton and James Joyce, could hardly bear to sleep under the roof of a house whose few bookshelves held thrillers and bound editions of the Reader’s Digest. I’m sure my family was glad to see the back of me when, at the end of the holiday, I packed up my books and headed back up to university in the north of England.

But the next year must have been even more painful to my parents: I didn’t show up at all. Now, I don’t think there’s anything wrong with young people spending a little time away from their families and with their friends.  It’s part of growing up, something you need to do if you are to become properly independent. However, if you’re not going to be home for the festival, you should at least have the decency to telephone and say you’re not coming.

In English we have an expression, “wet behind the ears.” A person who is wet behind the ears is so immature, that they don’t know how to dry the back of their head after a bath. Just before the following year’s holiday I fell ill, quite seriously so. I’m sure my own behavior contributed to my getting sick: staying out too late, not eating properly—perhaps you know someone like the person I was then. I lay in bed with a fever, feeling very sorry for myself.

I’m sure you can guess who came to my rescue. My long-suffering parents got in their car and sped up the motorway to rescue their son from the consequences of his own irresponsibility.

I hope I’m a better son now; if not, it’s getting a little late in the day if I want to change. I’ve worked in China for nearly 10 years and so I don’t get to see them as often as I like, but my parents are online all the time so we talk many times each week. And this Spring Festival I will be flying back to England for a visit. 

I’m really looking forward to it.

小题1:What can we learn from the first paragraph?

A.The author liked reading thrillers and the Reading Digest.

B.The author couldn’t fall asleep in a house with few books.

C.The author thought his parents were happy to see him back.

D.The author didn’t seem to share the same tastes with his parents.小题2:What can we learn from the second paragraph?

A.The next year the author’s parents were very happy to see him.

B.The author went to see his parents during the second year in college.

C.If you aren’t going to spent an important day with your family, inform them in advance.

D.To leave away from family is not a proper way if you want to gain some independency.小题3:If you are a person who is wet behind the ears, you are       .

A.old and experienced

B.young and inexperienced

C.young and experienced

D.mature and experienced小题4:We can infer from the last two paragraphs that       .

A.the author thinks he has become a good son

B.the author will be with his family the next Spring Festival

C.the author will not change himself to a better one because it is too late

D.the author keeps in touch with his parents through the Internet regularly小题5:What would be the best title for the text?

A.Pleasant memories about Christmas

B.Horrible things happened in the past

C.Interesting memories about Christmas

D.Share with you some of my Ghosts of Christmas Past

名词解释