问题 填空题

(1)在下列各物质中,能够供给人和动植物呼吸的是         (填写序号,下同),能够用于灭火的是            

①氧气     ②水   ③氮气  ④一氧化碳   ⑤二氧化碳

(2)生活中常见的一些铁制品如铁钉、铁锅、菜刀等若保管不当会生锈。铁制品生锈

的原因是                                 ;要防止铁制品生锈,在家庭中一般可采取的措施是                           (写出两种)。

(3)将生锈的铁钉投入到稀盐酸中,过一会儿才有气泡产生。

该过程的有关反应化学方程式为                                    

答案

(1)①   ②、⑤

(2)铁的化学性质活泼,能与空气中的氧气和二氧化碳反应生成铁锈

①擦净后放在通风干燥处;②涂上一层植物油(合理答案给分)

(3)Fe2O3 + 6HCl =" 2FeCl3" +3 H2O ;Fe + 2HCl =" FeCl2" + H2↑

(1)氧气能供给呼吸;水蒸发吸热,可降低可燃物的温度到着火点以下,能达到灭火的目的;二氧化碳不燃烧,也不支持燃烧,密度比空气大,可以隔绝氧气或空气,能达到灭火的目的.

(2)铁生锈实际上是铁与空气中的氧气和水反应,要防止铁生锈就要隔绝氧气和水,如擦净后放在通风干燥处;②涂上一层植物油.

(3)铁锈的主要成分是氧化铁,能与盐酸反应生成氯化铁和水,氯化铁可溶解于水,完全反应后铁露出来,铁与盐酸反应生成氯化亚铁和氢气,从而产生气泡,方程式分别是Fe2O3+6HCl=2FeCl3+3H2O;Fe+2HCl=FeCl2+H2↑.

故答案为:

(1)①;②、⑤;(2)铁的化学性质活泼,能与空气中的氧气和二氧化碳反应生成铁锈;①擦净后放在通风干燥处;②涂上一层植物油(合理答案给分);(3)Fe2O3+6HCl=2FeCl3+3H2O;Fe+2HCl=FeCl2+H2↑.

阅读理解

阅读理解

       I will never forget my first English class. It is very interesting. It’s the first class in the morning. The        teacher goes into the classroom with a smile on his face. At the beginning, he makes a self-introduction(自我介绍). And he tells us that his English name is John. Then he asks all of us to think of English names  for ourselves. We are very excited(兴奋的) to find a good name. Then he asks us to write our names down  on a piece of paper. I think about my English name for a long time. Then I come up with(想出) a beautiful name ---Shirley. All the students write their names down and give the paper to the teacher. When the teacher calls “Shirley” to answer his question, three girls stand up at the same time.

1. What do we do in the first English class?

A. Tell the teacher our Chinese names.    

B. Find English names for ourselves.

C. See an English film.                

D. Draw pictures.

2. What does our teacher do first?

A. He asks every student to make a self-introduction.

B. He introduces(介绍) himself to all of us.

C. He asks us many difficult questions

D. He tells us a story.

3. What’s the English name of our English teacher?

A. Jack.      

B. Shirley      

C. John.  

D. Tom.

4. Where do we write down our English names?

A. On the blackboard.          

B. On the desk.

C. On our hands.              

D. On the paper.

5. Which of the following is TRUE?

A. The teacher gives every student an English name.

B. Our teacher is a young girl.

C. Three girls choose(选择)the name “Shirley”.

D. The teacher calls our Chinese names in class.

名词解释