问题 填空题

金属钠的化学性质很活泼,它在空气中很容易变质,可以与冷水发生剧烈反应.

(1)钠在上述空气、冷水中发生反应中______(填“得”或“失”)电子,表现出______性(填“氧化”或“还原”).

(2)少量的金属钠应该保存在______中.

(3)写出钠与水反应的化学方程式______.

(4)当有0.2mol电子发生转移时,生成氢气的体积为______(标准状况)

答案

(1)钠最外层有1个电子,所以钠在反应中易失电子作还原剂,体现还原性,故答案为:失,还原;

(2)钠和水、氧气易反应,保存钠时要隔绝水和氧气,钠的密度大于煤油密度且和煤油不反应,所以少量钠通常保存在煤油中,故答案为:煤油;

(3)钠和水反应生成氢氧化钠和氢气,反应方程式为:2Na+2H2O=H2↑+2NaOH,

故答案为:2Na+2H2O=H2↑+2NaOH;

(4)设生成氢气的体积为x.

2Na+2H2O=H2↑+2NaOH转移电子

22.4L2mol

x 0.2mol

x=

22.4×0.2
2
L=2.24L,

答:生成2.24L氢气.

阅读理解

Once upon a time there was a monster(怪兽). He was very ugly and had no friends. No one wanted to talk to him. Even other monsters thought he was ugly.

He lived alone and was very unhappy because he was so lonely.

“I wish I had a friend.” He said to himself every day, “One friend would be enough. Someone to talk to.”

He wrote a letter to a magazine. The magazine gave people advice.

“Dear Editor,” he wrote, “I am a ugly monster. How can I find a friend?”

“Dear monster,” the Editor replied, “Advertise for a friend in this magazine.” The monster wrote an advertisement.

“Monster wants a friend, male or female. I have two heads, four arms, six legs and three tails. I have one blue eye, one green eye and one brown eye. Smoke comes out of my nose. But I am really a kind monster and will be a good friend to someone. If you would like to meet me, please stand outside Blake’s Store at 6 p.m. on Friday, May 7th. Write to Mr. A, Box 45, everybody’s Magazine.”

A few days later he went to the magazine.

“Do you have any letters for Box 45?” he asked.

The clerk looked in Box 45.

“Yes, there is one.” She said, and gave it to him.

The monster opened the letter, and read, “Dear Monster, I think a person’s character is more important than his appearance. I will wait outside Blake’s Store on Friday. Please carry a flower so that I will recognize you. Yours sincerely, Miss Alice Thwaite.”

小题1:Why was the monster unhappy?

A.He had no friends.

B.He was ugly.

C.He had two heads.

D.He had three tails.小题2:What did the monster advertise for?

A.A magazine.

B.A friend.

C.An editor.

D.A male or female monster.小题3:How did the monster describe him in the advertisement?

A.Ugly

B.Lonely

C.Kind

D.Good-looking小题4:What was strange about Miss Thwaite’s letter?

A.She was not interested in people’s appearance.

B.She wanted to meet the monster.

C.She needed a flower to recognize him.

D.It was the only reply.

单项选择题