问题 填空题

已知CO和H2的混合气体称为水煤气,可由碳(C)与水蒸气(H2O)在高温下反应生成.如下图:

已知:单质E可作为半导体材料,化合物F是有毒的氧化物,C为液态.据此,请填空:

(1)氧化物A是______

(2)化合物F是______

(3)反应①的化学方程式是______

(4)反应②的化学方程式是______

(5)反应③的化学方程式是______.

答案

根据单质E可作为半导体材料,所以E是硅;C为液态的氧化物,常温下呈液态的氧化物只有水,所以C是水;单质G和H反应生成水,所以单质G和H,所以两种单质中一个是氧气和一个是氢气;氧化物A和单质B反应生成硅和氧化物F,根据元素守恒知,A是二氧化硅;

二氧化硅和单质B反应生成硅和化合物,且F是有毒的氧化物,有毒的氧化物有一氧化碳、一氧化氮、二氧化氮、二氧化硫,且单质B和水能反应生成氧化物F和单质G,结合元素守恒知,B是碳,F是一氧化碳,G是氢气,H是氧气.

(1)通过以上分析知,A是SiO2,故答案为:SiO2

(2)通过以上分析知,F是CO,故答案为:CO;

(2)碳和二氧化硅在高温下反应生成一氧化碳和硅,故答案为:2C+SiO2

 高温 
.
 
2CO+Si;   

(3)碳和水蒸气在高温下反应生成一氧化碳和氢气,故答案为:C+H2O

 高温 
.
 
CO+H2

(4)氢气在氧气中燃烧生成水,故答案为:2H2+O2

 点燃 
.
 
2H2O.

阅读理解

Let’s say you have a piece of wood, a nail, and hammer. Pretend the wood is a person, the nail is a mean rumor (谣言) about that person. If you hammer in the nail, you’re obviously hurting him or her. If you then pull out the nail, there’s still a hole in the wood, and the damage has been done.

There are many reasons why that nail of a rumor can be so harmful. Rumors are, quite simply, a form of bullying (欺悔). When a person or a group makes up a rumor about someone or decides to spread gossip, it’s usually to hurt someone, break up a friendship, or make someone less popular. It’s the same thing as teasing, only it’s done behind someone’s back instead of to his or her face.

When you spread a rumor about someone, you’re sending a signal that the person is outside of the group, and somehow less worthy of friendship than others. You’re making fun of that person or pointing out negative things about him or her. This can let others think that it’s okay to make the person feel bad, and make him or her an outsider.

We need to be able to trust our friends, and gossip and rumors can break this trust. If you tell a personal secret to a friend, and he turns around and tells it to someone else, you might feel like you will get burned if you ever get close to him again.

Letting a rumor influence your behavior is like letting someone else make a big decision for you. Let’s say you hear that the teacher plans to call a Snow Day tomorrow because a blizzard (暴风雪) is coming. Expecting a day off, you don’t do your homework. The next morning, the blizzard turns out to be nothing more than a drizzle(毛毛雨), and school isn’t off after all. You get zeroes on your work.

小题1:The purpose of the first paragraph is to        .

A.help readers know what a rumor is

B.attract readers to read the following paragraphs

C.emphasize the damaging effects of rumors

D.explain how a rumor spreads小题2:To tell a rumor and a tease apart, you depend on        .

A.whether it is done behind someone

B.whether it is painful or not

C.whether it is a kind if bullying

D.whether it is spread fast小题3: If a rumor is spread about someone, others may        .

A.point out his or her advantages

B.keep away from him or her

C.not feel he or she is an outsider

D.be hurt if getting close to him or her again小题4:From the last paragraph, we can infer that        .

A.it is hard to keep rumors a secret

B.rumors can destroy your interest in learning

C.believing rumors can lead to bad choices

D.rumors can control your whole life小题5:The purpose of this passage is to         .

A.advise on how to deal with rumors

B.teach us how to judge a rumor

C.find out why rumors spread fast

D.explain why rumors hurt

判断题