问题 问答题

(本题有a、b两小题,考生任选一题解答,不得两题都解,若两题都解,则以a小题计分)

a.油脂是重要的营养物质.油脂在人体内完全氧化时,每克放出约39.3kJ的能量,如果油脂的化学式为C57H110O6则:

(1)该油脂由 ______种元素组成,其相对分子质量为 ______;

(2)正常人一般每天消耗9432kJ能量,如果能量的25%由油脂提供,那么我们每天大约需要摄入 ______g油脂,才能维持机体能量平衡.

b.无土栽培的某种营养液中,含硝酸钾的质量分数为7.1 0%.

(1)某蔬菜种植大户需配制该营养液500kg,需要硝酸钾的质量是 ______;

(2)这些硝酸钾中含氮元素的质量是 ______;(精确至0.01kg)

(3)硝酸钾属于 ______(在“单质”“化合物”“氧化物”中选填).

答案

a.(1)根据油脂的化学式为C57H110O6进行分析可知油脂由C,H,O三种元素组成;

根据相对分子的质量为组成分子的各原子的相对原子质量之和,则油脂的相对分子质量=12×57+1×110+16×6=890;

故答案为:3; 890;

(2)正常人一般每天消耗的由油脂提供能量:9432kJ×25%=2358 kJ,

每天大约需要摄入油脂的量为:2358 kJ÷39.3kJ=60 g;

故答案为:60 g.

b.(1)根据溶质的质量分数=

溶质质量
溶液质量
×100%,可求得配制该营养液500kg需要硝酸钾的质量为:500kg×7.1%=35.5kg;

故答案为:35.5kg;

(2)根据物质中某元素的质量分数=

该元素的相对原子质量×原子个数
该物质的相对分子量
×100%,

可求得硝酸钾氮元素的质量分数=

14
39+14+16×3
×100%=13.86% 

溶质硝酸钾中含氮元素的质量=35.5kg×13.86%=4.92 kg;故答案为:4.92 kg;

根据化合物是由两种或两种以上的元素组成的纯净物,因此硝酸钾属于化合物;故答案为:化合物.

完形填空

A boy walked along Carver Street, singing a sad song. He walked with his head down. Once he looked up and noticed the sign across the empty street, painted on the side of an old house. On the sign a big woman with yellow hair and a five-mile smile held out a big bottle. “Coca-Cola. Drink Coca-Cola,” the sign said.

“Boy!” the silence was cut by a sudden cry. He turned around quickly to see who had called.

An old woman was standing at her door.

“You boy! Come here this minute!”

Slowly the boy ___1___ onto the cold flat stones leading to the old woman’s house. When he arrived at her house, she ___2___ out her hand and wrapped(缠住) her ___3___ old fingers around his arm.

“Help me inside, boy”, she said, “Help me ___4___ to my bed. What’s your name?”

“Joseph,” he said.

The old woman on the bed tried to ___5___ up, raising herself on her elbow(肘). Water ___6___ from her eyes and mouth. The sight of her made Joseph feel ___7___.

“I am dying, Joseph. You can see that, can’t you? I want you to write a ___8___ for me. There’s paper and pencil on the table there.”

Joseph looked down at the ___9___, and then looked out the window. He saw the sign again: “Coca-Cola. Drink Coca-cola.”

“I want my silver pin to ___10___ to my daughter.”

Joseph bent his small body over the table and ___11___ the pencil slowly across the paper.

“There’s my Bible(圣经),” the old woman said. “That’s for my daughter, too. I want a ___12__ Christian burial(基督葬礼) with lots of singing. Write that down, too. That’s the last ___13__ of a poor old woman.”

The boy labored over the paper. Again he looked out the window.

“Here. Bring it here so I can ___14___ it.”

Joseph found the Bible, and ___15___the paper inside, laid it next to the bed.

“___16___ me now, boy,” she sighed. “I’m tired.”

He ran out of the house.

A cold wind blew through the ___17___ window, but the old woman on the bed ___18___ nothing. She was dead. The paper in the Bible moved back and forth in the wind. ___19___ on the paper were some childish letters. They ___20___ the words “Coca-Cola. Drink Coca-cola.”

1. A. rushed    B. struggled    C. hurried       D. stepped

2. A. reached  B. let      C. pushed       D. pointed

3. A. firm       B. smooth       C. dry     D. fresh

4. A. back       B. over    C. away   D. ahead

5. A. sit   B. get      C. stand   D. wake

6. A. rolled     B. burnt  C. burst   D. ran

7. A. ill   B. sick    C. unpleasant  D. funny

8. A. letter      B. note    C. will    D. message

9. A. table      B. pen     C. paper  D. woman

10. A. send     B. go      C. belong       D. come

11. A. moved  B. drew   C. used    D. pulled

12. A. great    B. merry C. splendid     D. real

13. A. hope     B. chance       C. opinion      D. wish

14. A. sign      B. read    C. remember   D. copy

15. A. setting  B. hiding C. placing       D. laying

16. A. Hold    B. Leave  C. Excuse       D. Pardon

17. A. large    B. open   C. small  D. pretty

18. A. did       B. saw     C. felt     D. knew

19. A. Described    B. Printed       C. Recorded    D. Written

20. A. formed B. spelled       C. organized   D. repeated

单项选择题