问题 填空题

Ⅰ溴被称为海洋元素,向盐卤中通入氯气可制得溴:Cl2 + 2NaBr = 2NaCl + Br2,该反应被氧化的元素为

__________(写元素符号);若上述反应制得16g Br2,则转移的电子数目是_________个。

Ⅱ请按要求书写化学方程式或离子方程式

(1)小明运用化学实验证明了久置于空气中的漂白粉已变质,请用化学方程式表示漂白粉变质的原因

__________________。

(2)FeSO4溶液用稀H2SO4酸化,放置一段时间后略显黄色,写出变化过程的离子方程式__________________;然后向其中滴加KI-淀粉溶液变蓝色,写出变化过程的离子方程式___________________。

答案

Ⅰ Br;0.2NA或1.204×1023

Ⅱ(1)Ca(ClO)2+CO2+H2O=CaCO3+2HClO、2HClO2HCl+O2↑ 

(2)4Fe2++ 4H+ + O2 =4Fe3++2H2O;2Fe3++2I-=2Fe2++I2

改错题
短文改错。此题要求改正所给短文中的错误。对标有题号的每一行作出判断:如无错误,在该
行右边横线上画一个勾(√);如有错误(每行只有一个错误),则按下列情况改正:
此行多一个词:把多余的词用斜线(\)划掉,在该行右边横线上写出该词,并也用斜线划掉。
此行缺一个词:在缺词处加一个漏字符号(^), 在该行右边横线上写该加的词。
此行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。
注意:原行没有错的不要改。
I went shopping with my wife. We have a lot of things to      
buy them. We drove to the center of the city and stopped    
 our car in front of the shop. An hour late, we came back        
to the car. But it is strange that we couldn't open           
the door. So we asked policeman for help. He was                
glad to help us. A few minute later, he got the door open.      
Just then a man came up and shouted angrily. "How are        
you doing with my car?" We were surprising and went to         
see the number of the car. What you think we did then?        
We had to speak sorry to the man again and again.             
1. _________    
2. _________     
3. _________     
4. _________  
5. _________                                        
6. _________   
7. _________     
8. _________   
9. _________    
10. _________    
单项选择题