问题 选择题

Na2FeO4是一种高效多功能水处理剂.一种制备Na2FeO4的方法可用化学方程式表示如下:2FeSO4+6Na2O2=2Na2FeO4+2Na2O+2Na2SO4+O2↑,下列说法中不正确的是(  )

A.Na2O2在反应中只作氧化剂

B.Na2FeO4既是氧化产物又是还原产物

C.O2是氧化产物

D.2molFeSO4发生反应时,共有10mol电子转移

答案

AD

解析:2FeSO4+6Na2O2=2Na2FeO4+2Na2O+2Na2SO4+O2↑反应中,Fe元素的化合价升高,有+2价升高到+3价,Na2O2中O元素的化合价既升高又降低.
A、Na2O2中O元素的化合价既升高又降低,反应中既是氧化剂又是还原剂,故A错误;
B、FeSO4→Na2FeO4,Fe的化合价升高,Na2FeO4是氧化产物,Na2O2→Na2FeO4,O元素化合价降低,Na2FeO4是还原产物,故B正确;
C、Na2O2→O2,O元素化合价升高,O2是氧化产物,故C正确;
D、反应中化合价升高的元素有Fe,由+2价→+6价,化合价升高的元素还有O元素,由-2价→0价,2molFeSO4发生反应时,共有2mol×4+1mol×4=12mol电子转移,故D错误.
故选AD.
完形填空
完形填空。
     Mike always loves ships. When he was    1   , he said,"l'm going into the army. "But his eyes were not
   2  ,and he could not get in.
     Then he said,"l'm going to buy a small   3   ,and I'm going to go around the world. "But boats  4   
very expensive,and Mike did not have   5   money.
      But last summer Mike found a swimmg  club(俱乐部)near   6   house.The lessons did not cost very much,and Mike began going to the club at the weekends and    7  Now he is a good swimmer.
      Last week a little boy said to him,"You are a very good swimmer. How did you leam to swim   8  
"Mike said and he smiled,"Whenever I'm in the water,l say to   9  ,There are dangerous fishes in this
area(地区) !'  Then I'm very   10   ,and I try to swim fast. "
( )1. A.dead            
( )2. A.good            
( )3. A.plane            
( )4. A.are              
( )5. A.many            
( )6. A.his              
( )7. A. having meetings
( )8. A.so slowly        
( )9. A.me              
( )10. A.afraid          
B. younger      
B. bad          
B. train        
B. is          
B. much        
B. her          
B. watching TV
B. so fast      
B. myself      
B. busy        
C. older 
C. broken          
C. boat            
C. were            
C. any            
C. him            
C.  having lessons
C. not so fast    
C. him            
C. poor            
D. ill            
D. weak          
D. car            
D. was            
D. few            
D. she            
D. seeing films  
D. not so well    
D. himself        
D. rich          

判断题