试题与答案

下列化学方程式书写正确的是( ) A.氯酸钾与二氧化锰的混合物共热:2KClO3

题型:选择题

题目:

下列化学方程式书写正确的是(  )

A.氯酸钾与二氧化锰的混合物共热:2KClO3

 MnO2 
.
2KCl+3O2

B.铁在氧气中燃烧:4Fe+3O2

 点燃 
.
 
2Fe2O3

C.碳在氧气中不充分燃烧:C+O2

 点燃 
.
 
CO2

D.碳酸不稳定分H2CO3

  △  
.
 
H2O+CO2

答案:

A、未标气体符号,正确的方程式为:2KClO3

 MnO2 
.
2KCl+3O2↑,故A错误;

B、铁在氧气中燃烧生成四氧化三铁,正确的化学方程式为:3Fe+2O2

 点燃 
.
 
Fe3O4,故B错误;

C、碳在氧气中不充分燃烧生成的是一氧化碳,正确的化学方程式为:2C+O2

 点燃 
.
 
2CO,故C错误;

D、化学方程式书写完全正确,故D正确;

故选D.

试题推荐
题型:阅读理解

阅读理解。

     Mark Twain was a great writer. He was born in 1835 in the

USA. He was also a famous speaker. He was famous for his sense

of humour. Many people liked to listen to his talk because he liked

to tell some interesting stories to make people laugh all the time.

     One day,Mark Twain was going to a small town because of

his writing. Before he was going to leave, one of his friends said to

him that there were always a lot of mosquitoes in the town and told

him that he'd better not go there. Mark Twain waved his hands and

said, "It doesn't matter. The mosquitoes are no relatives of mine. I

don't think they will come to visit me. "

     After he arrived at the town,Mark Twain stayed in a small

hotel near the station. He went into his room,but when he was just

about to have a rest,  quite a few mosquitoes flew around him. The

waiters felt very sorry about that. "I'm very sorry, Mr Mark Twain.

There are too many mosquitoes in our town," one of them said

to him.

     Mark Twain, however, made a joke, saying to the waiter,

"The mosquitoes are very clever. They know my room number.

They didn't come into the wrong room. " What he said made all the

people present laugh heartily.

     But that night Mark Twain slept well. Do you know why?

That was because all the waiters in the hotel were driving the

mosquitoes away for him during the whole night.

1. Why did many people like to listen to Mark Twain's talk?  

A. Because he a great writer.

B. Because he liked to anyone.

C. Because of his sense of humour.

D. Because he wrote good novels.

2. That day Mark Twain went to the town _____.   

A. to see one of his friends

B. because he wanted to do something there for his writing

C. because he was told there were a lot of mosquitoes there

D. to see one of his relatives

3. The waiters felt sorry because _____.      

A. they did something wrong to Mark Twain

B. their hotel was too small

C. the room was not very clean

D. there were quite a few mosquitoes in Mark Twain's room

4. All the people present laughed heartily because ____.  

A. the mosquitoes were very clever and they didn't come into the wrong room

B. the mosquitoes knew Mark Twain's room number

C. Mark Twain gave the waiters some nice presents

D. Mark Twain made a joke.

5. From the story we know _____  .

A. no mosquitoes troubled Mark Twain in the night

B. the owner of the hotel told the waiters to look after MarkTwain well at night

C. Mark Twain didn't have a good rest that night

D. there were not mosquitoes in the hotel any longer

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