问题 问答题

图10是实验室常用的实验仪器与装置,根据所学知识回答下列问题:

(1)请写出有编号的仪器名称:a           b         

(2)在实验室里,通常用下列方法制氧气:①双氧水和二氧化锰混合;②氯酸钾和二氧化锰混合加热;③加热高锰酸钾;其中最能体现“节能、环保、低碳”理念的制备方法是__   __(填序号),写出该反应的化学方程式:      。

(3)当用A和C装置制取氧气时,发现水槽中的水变成紫红色,为避免此现象发生,应对该实验装置作出的一点改动是           。

(4)为检验CO2气体,可把气体通入F装置中,则F中的试剂是____  ______, F中反应的现象是_______     _______________。

(5)阅读以下资料并回答:

物质制取气体的药品反应条件气体的物理性质
氯气二氧化锰固体、

浓盐酸

需要加热密度比空气大、

可溶于水

制取氯气____________(填“可以”或“不可以”,下同)采用B装置,收集氯气_____  ______采用E装置。

答案

(1)酒精灯、集气瓶 (2)①、2H2O22H2O+O2↑(3)在试管口放一团棉花

(4)澄清石灰水 (5)澄清石灰水变浑浊 (6)不可以、可以

分析:(1)根据常用仪器的名称解答;

(2)根据实验室制取氧气的反应原理进行分析,并根据方程式的书写原则书写方程式;

(3)根据加热高锰酸钾制取氧气试管口放棉花的作用进行解答;

(4)根据检验二氧化碳用澄清的石灰水进行解答;

(5)根据收集装置和发生装置的选择标准进行判断.

解答:解:(1)根据常用仪器可判断分别为:酒精灯,集气瓶;

(2)②③都需要加热,而用过氧化氢制取氧气,不需要加热,节约能源,较好体现低碳生活理念,且生成水,无污染,环保;双氧水和二氧化锰混合生成水和氧气,反应的方程式为:2H2O22H2O+O2↑;

(3)用高锰酸钾制取氧气时,为了防止加热时高锰酸钾粉末进入导管,试管口要放一团棉花;

(4)二氧化碳与澄清的石灰水反应产生不溶于水的碳酸钙沉淀和水,故常用澄清的石灰水检验二氧化碳气体;

(5)实验室用二氧化锰固体和浓盐酸混合加热制取氯气,发生装置属于固体和液体加热制取气体;故不能用B装置;氯气可溶于水,不可采用排水法收集,密度比空气大,可以采用向上排空气法收集.

故答案为:

(1)酒精灯、集气瓶; 

(2)①、2H2O22H2O+O2↑;

(3)在试管口放一团棉花;

(4)澄清石灰水;澄清石灰水变浑浊; 

(5)不可以、可以.

判断题
完形填空
完形填空
     When I first came to the USA, I made friends with a neighbor who used to live only two blocks away
from my street. This friend taught me a lot about American __1__, but in some __2__I had to learn the
hard way, because we didn't have enough time together for me to learn all about American customs from
him.
     One day this same friend invited me to a party. It wasn't a (n)__3__party, only some kind of informal
gettogether. Since it was summer time he had a cookout where most of his American friends and relatives
were known to me, but there were others I had never met before.
     It was the most __4__party for me when I noticed that. Everybody was wearing jeans and simple
Tshirts for the day,__5__I arrived in proper dress with my shoes and my hair all fixed for a fancy party.
It was hard to __6__my embarrassment to the other guests. When one of them turned around and said,
"What nice clothes! What's the occasion?" I felt my __7__ burning hot. I didn't answer at all. If she knew
how bad I already felt, she wouldn't have come near me. But she did. Maybe she didn't ask __8__to
make me feel bad or uncomfortable, but my reaction had to do with the way I already felt.I could have
told her I had to go to another party afterward, but I did not want to continue the __9__.
     Many times I thought of going home and __10__but I knew they would notice. It would be even
__11__for me because I knew they would quickly think that I felt out of __12__. So I wanted to pretend
that I was OK.
     I have already realized their customs are different from mine, but after I talked to my friend, I was
more convinced that people here are more __13__. They care less about formality __14__it is a special
occasion, like a __15__or a very formal invitation.
( )1. A. art    
( )2. A. ways        
( )3. A. real        
( )4. A. exciting    
( )5. A. as          
( )6. A. explain      
( )7. A. heart        
( )8. A. carefully    
( )9. A. conversation
( )10. A. changing    
( )11. A. worse      
( )12. A. order      
( )13. A. indifferent
( )14. A. unless      
( )15. A. party      
B. culture      
B. conditions    
B. pleasant      
B. surprising    
B. while        
B. talk          
B. body          
B. intentionally
B. speech        
B. crying        
B. luckier      
B. breath        
B. casual        
B. if            
B. picnic        
C. history      
C. cases        
C. usual        
C. embarrassing  
C. when          
C. speak        
C. face          
C. willingly    
C. meeting      
C. sleeping      
C. better        
C. place        
C. open          
C. as long as    
C. meeting      
D. people    
D. methods    
D. evening    
D. enjoyable  
D. and        
D. say        
D. hand      
D. eagerly    
D. discussion
D. dancing    
D. easier    
D. mind      
D. careless  
D. since      
D. wedding