问题 实验题

(13分) 用如右图装置进行铜与一定体积已知浓度的浓硫酸反应的实验研究。

(1)写出试管B中的实验现象             

(2)写出A处反应的化学方程式,并用双线桥标明电子转移的方向和数目:                        

(3)充分反应后,该学生发现铜和硫酸都有剩余。在不补充浓硫酸的前提下,若要使剩余的铜片溶解,可再加入(要求填写一种不是酸类的物质)        

(4)B试管口的棉花应沾有的试剂是        ,其作用是                   ,离子方程式为                         

答案

(1)品红溶液褪色

(2)

(3)NaNO3、Fe2O3、FeCl3(其它合理答案均可)

(4)NaOH溶液 吸收尾气,防止污染   2OH+SO2=SO32+H2O

题目分析:(1)试管B中的现象是品红溶液褪色。(2)A处反应的化学方程式及双线桥为:。(3)铜和浓硫酸反应时,当硫酸稀到一定程度时,该反应停止,如果想让铜继续溶解可以加入氧化剂,如NaNO3、Fe2O3、FeCl3等。(4)SO2是大气污染物,所以应该用NaOH溶液吸收,反应的离子方程式为:2OH-+SO2=SO32-+H2O。

点评:本实验比较基础,难度小,可作为对学生进行基础训练的习题。

阅读理解

阅读理解。

      Last summer vacation, I volunteered to work at a vet's (兽医诊所). There I saw a lot of dogs. Minnie

was the funniest-looking dog I'd ever seen. Short thin curly hair covered her sausage-shaped (香肠形) body.

Her eyes always seemed surprised. And her tail looked like a rat's tail. 

     She was brought to the vet because her owners didn't want her any more. I thought Minnie had a sweet

personality, though. "No one should judge her by her looks," I thought. Finally, I advertised Minnie in the local

paper. "Funny-looking dog, well-behaved, needs a loving family."

     When a boy called, I warned him that Minnie was strange-looking. The boy on the phone told me that his

grandfather's sixteen-year-old dog had just died. They wanted Minnie no matter what. I gave Minnie a good

bath. Then we waited for them to arrive. At last, an old car pulled up in front of the vet's. Two kids raced to

the door. They picked Minnie up and rushed her out to their grandfather, who was waiting in the car. I hurried

behind them to see his reaction to Minnie. Inside the car, the grandfather held Minnie in his arms and stroked

her soft hair. She licked (舔) his face. Her tail wagged (摇摆) around so quickly that it looked like it might fly

off her body.

     "She's perfect!"the old man said happily.

      I was thankful that Minnie had found a good home.

      Suddenly, I saw that the grandfather's eyes were a milky white colour-he was blind.

1. The last three sentences in the first paragraph tell us  _______.

A. how funny Minnie looked

B. how well Minnie behaved

C. Minnie was a beautiful dog

D. Minnie was dying

2. Why did the writer advertise Minnie in the local newspaper?

A. Because he wanted to sell her at a good price.

B. Because he didn't want her any more, either.

C. Because he wanted to find a family for her.

D. Because he wanted to have another dog.

3. Why did the boy who called the writer want Minnie?

A. Because he loved all kinds of dogs very much.

B. Because he had seen Minnie and loved her very much.

C. Because his grandfather's dog was too old.

D. Because his grandfather's dog had just died.

4. The underlined word "stroke" may mean  _______.

A. 抚摸

B. 拔

C. 剪

D. 揪

5. Which of the following is TRUE?

A. Minnie wasn't the type of dog the old man loved.

B. The old man couldn't see how funny Minnie looked.

C. Minnie knew very well how to make others dislike her.

D. Minnie was like the old man's dog which had just died.

问答题 简答题