问题 填空题

(3分)某化学兴趣小组进行了如图所示的喷泉实验,将胶头滴管中的水挤入烧瓶,然后打开止水夹,在烧瓶内出现美丽的红色喷泉。

(1)请从上述现象中推测氨气具有的两点性质:

(2)下列常用干燥剂中不能干燥氨气的是(    )

A.浓硫酸            B.固体氢氧化钠            C.生石灰

答案

(1)氨气易溶于水  氨气的水溶液显碱性  (2)A

:(1)从挤压胶头滴管能形成喷泉,其原因是烧瓶内气压变小,导致气压变化的是氨气极易溶于水,由于生成了红色喷泉说明氨水能使酚酞试液变红,可知氨水呈碱性;

(2)选用干燥剂时被干燥气体不能与干燥剂反应,所以浓硫酸不能用于干燥氨气,固体氢氧化钠和生石灰均不能与氨气反应,所以可用于干燥氨气;

故答案为:(1)氨气易溶于水;氨气的水溶液显碱性;(2)A;

阅读理解

阅读短文,选择正确答案。

    Happiness is for everyone. You don' t need to care about those people who have beautiful houses with large

gardens and swimming pools or those who have nice cars and a lot of money and so on. Why? Because those

who have big houses may often feel lonely and those who have cars may want to walk on the country roads at

their free time.

    In fact, happiness is always around you if you put your heart into it. When you are in trouble at school, your

friends will help you; when you study hard at your lessons, your parents are always taking good care of your life

and your health; when you get success, your friends will say congratulations to you; when you do something

wrong, people around you will help you to correct it. And when you do something good to others, you will feel

happy, too. All these are your happiness. If you notice a bit of them, you can see that happiness is always around

you.

    Happiness is not the same as money. It is a feeling of your heart. When you are poor, you can also say you

are very happy, because you have something else that can' t be bought with money. When you meet with

difficulties, you can say loudly you are very happy, because you have more chances to challenge yourself. So

you cannot always say you are poor and you have bad luck. As the saying goes, life is like a revolving (旋转的)

door. When it closes, it also opens. If you take every chance you get, you can be a happy and lucky person.

1. Those who have big houses may often feel _______. [ ]

A. happy

B. lonely

C. free

D. excited

2. When you fall down in a PE class, both your teacher and your classmates will ______. [ ]

A. laugh at you

B. play jokes on you

C. quarrel with you

D. help you up

3. What will your friends say to you when you make great progress? [ ]

A. Oh, so do I.

B. Congratulations.

C. Good luck.

D. It's just so so.

4. Which idea is NOT RIGHT according to the passage? [ ]

A. People who have cars would never like to walk in the open air.

B. You can get help from others when you make mistakes.

C. You can still be a happy person even if you have little money.

D. Happiness is always around you though difficulties come towards you.

5. Which of the following is this passage about? [ ]

A. Bad luck.

B. Good luck.

C. Happiness.

D. Life.

单项选择题