问题 选择题

镍(Ni)是重要的金属,镍及其化合物发生下列反应:

①Ni+2HCl═NiCl2+H2

②NiO+2HCl═NiCl2+H2O

③NiO2+4HCl═NiCl2+Cl2+2H2O

对上述反应的分析错误的是(  )

A.镍能与氯化铜溶液发生置换反应

B.反应①、③中镍的化合价都发生了变化

C.反应②和③都是复分解反应

D.置换反应中,必有某些元素的化合价在反应前后发生变化

答案

A、根据题目给出的信息,镍与酸反应说明镍排在氢的前面,铜排在氢的后面,因此镍能与氯化铜溶液发生置换反应;故A说法正确;

B、反应①中镍的化合价由0价到+2钾;反应③中镍的化合价由+4价到了+2价;故B说法正确;

C、②是复分解反应,③不是,故C说法错误;

D、置换反应是一种单质和一种化合物反应生成另一种单质,和另一种化合物,单质的化合价为零,所以置换反应中,必有某些元素的化合价在反应前后发生变化,故D说法正确;

故选C.

完形填空

Directions: Complete the following passage by filling in each blank with one word that best fits

the context.

On the first day of classes at a Los Angeles high school, several American boys came up to a Chinese boy and said: “Hi, what’s up?”   48   hearing their greeting, the boy,   49    had just moved to the US with his parents, raised his head and looked at the sky.

This is a story told by David Chen,  50  31-year-old actor in Taiwan who recently launched a Sina mini-blog, on which he teaches easy English expressions.

  51  me, the mini-blog is like a mirror.When I read the comments, I see myself more clearly.”

Chen made a breakthrough last year    52  he had a double-eyelid surgery.“I like making changes and I think it’s necessary,” he said.“I know many fans like my pretty boy image.But now I’m growing up, I want to look rougher and  53 mature.”

“When you have a new haircut, you do not need to explain it.__54___ is just like changing your mood to do so–if you feel happy, that’s great,” said Chen.“Young people should realize    

that sometimes you can just do what you want to do.You will eventually get support from others if you dare to be   55  .”

PART THREE READING COMPREHENSION

Directions: read the following three passages.Each passages is followed by several questions or unfinished statements.For each of them there are four choices marked with A, B, C and D.choose the one that fits best according to the information given in the passage.

问答题 简答题