问题 填空题

小渝同学使用废干电池皮(锌)、铁锈(主要成分是氧化铁)、洁厕剂(含有盐酸)、高锰酸钾(药店可购得)四种物质来制取四氧化三铁.请你写出各步反应的化学方程式.

(4)制氢气:______;

(5)制铁(粉):______;

(6)制氧气:______;

(7)制四氧化三铁:______.

答案

(4)锌与稀盐酸反应生成氯化锌和氢气.

该反应的化学方程式为:Zn+2HCl=ZnCl2+H2↑.

(5)氧化铁与氢气在高温条件下反应生成铁和水.

该反应的化学方程式为:Fe2O3+3H2

 高温 
.
 
2Fe+3H2O.

(6)高锰酸钾在加热条件下反应生成锰酸钾、二氧化锰和氧气.

该反应的化学方程式为:2KMnO4

  △  
.
 
K2MnO4+MnO2+O2↑.

(7)铁与氧气在点燃条件下反应生成四氧化三铁.

该反应的化学方程式为:3Fe+2O2

 点燃 
.
 
Fe3O4

故答案为:

(4)Zn+2HCl=ZnCl2+H2↑;

(5)Fe2O3+3H2

 高温 
.
 
2Fe+3H2O;

(6)2KMnO4

  △  
.
 
K2MnO4+MnO2+O2↑;

(7)3Fe+2O2

 点燃 
.
 
Fe3O4

阅读理解

George worked in London. He wasn't married, and usually had his lunch, and sometimes his dinner, in small restaurants. One evening he decided to go to an expensive restaurant, and when he got in, he saw a large, heavy man whom he had not seen for several years sitting by himself at a  table. He thought for a few moments and then remembered the man's name. So he went up to him and said politely, "Hello, Mr Grey. How is your business?"

"Oh, it's not good at all," the large man answered.

George looked at the expensive food and wine on Mr Grey's table and was surprised. "It certainly doesn't look like what you said," he said.

"Well," Mr Grey answered sadly, "I'm afraid you are wrong. A few years ago I was doing very well, and I could afford to bring my wife to this place for dinner too."

小题1:George usually had his lunch in small restaurants because ______.       

A.he wasn't able to do some cooking

B.he had no wife

C.he liked to do so

D.there were only small restaurants around小题2:______ one evening.

A.George was invited to dinner in an expensive restaurant

B.George invited some friends to have dinner in an expensive restaurant

C.George went to an expensive restaurant himself

D.George ate a lot of expensive food and wine小题3:Mr Grey told George ______.

A.his business wasn't as good as before

B.his wife wasn't well at all

C.he hadn't seen him for some years

D.he was used to eating expensive food and wine小题4:Mr Grey's wife ______.

A.often had dinner in small restaurants

B.always had dinner in expensive restaurants with her husband

C.knew George very well

D.used to have dinner with her husband in the expensive restaurant小题5:When Mr Grey said his business wasn't good at all, George ______.   

A.didn't believe what he said

B.was not surprised to hear that

C.agreed with what he said

D.was asked to have dinner with him

多项选择题