问题 问答题

某气体可能含有氢气、一氧化碳、二氧化碳、水蒸气和氯化氢中的一种或几种,为了确定其成分,将该气体依次进行如下实验(假设各步均完全反应):

①通过浓硫酸,浓硫酸质量增加;②通过澄清石灰水,石灰水不变浑浊;③先通过浓硫酸,再通过灼热的氧化铜,固体由黑色变成红色;④通过无水硫酸铜,固体不变色(无水硫酸铜具有遇水变蓝的性质);⑤通过澄清石灰水,石灰水变浑浊.

请根据上述实验现象推断,并用化学式填空:该气体中一定有______,一定没有______,无法确定的是______.

答案

由①得出结论是一定有水蒸气;由②得出结论是若没有氯化氢,就一定没有二氧化碳;若有氯化氢,还不一定有二氧化碳,故原气体中的二氧化碳和氯化氢都不能确定;由③得出的结论是一定有还原性气体;由④得出的结论是一定没有氢气,一定有一氧化碳;⑤进一步确定含有一氧化碳.

故答案为:H2O   CO;      H2;   CO2 HCl

阅读理解

M When Paul was a boy growing up in Utah, he happened to live near a copper smelter(炼铜厂), and the chemicals that poured out had made a wasteland out of what used to be a beautiful forest. One day a young visitor looked at this wasteland and called it an awful area. Paul knocked him down. From then on, something happened inside him.

Years later Paul was back in the area, and he went to the smelter office. He asked if they had any plans or if they would let him try to bring the trees back.. The answer from that big industry was “No.”

Paul then went to college to study the science of plants. Unfortunately, his teachers said there weren't any birds or squirrels to spread the seeds. It would be a waste of his life to try to do it. Everyone knew that, he was told. Even if he was knowledgeable as he had expected, he wouldn’t get his idea accepted.

Paul later got married and had some kids. But his dream would not die. And then one night he did what he could with what he had. As Samuel Johnson wrote, “It is common to overlook what is near by keeping the eye fixed on something remote. Attainable good is often ignored by minds busied in wide ranges.” Under the cover of darkness, he went secretly into the wasteland and started planting.

And every week, he made his secret journey into the wasteland and planted trees and grass. For fifteen years he did this against the plain common sense. Slowly rabbits appeared. Later, as there was legal pressure to clean up the environment, the company actually hired Paul to do what he was already doing.

Now the place is fourteen thousand acres of trees and grass and bushes, and Paul has received almost every environmental award Utah has. It took him until his hair turned white, but he managed to keep that impossible vow he made to himself as a child.

小题1:When Paul was a boy, _____.

he had decided never to leave his hometown

the economy of Utah depended wholly on the copper smelter

no laws were made to protect the environment against pollution

he had determined to stop the copper smelter polluting the area

小题2:Why did Paul go to college to study the science of plants?

He wanted to find out the best way to save the area himself.

He was interested in planting trees since he was young.

He wanted to get more knowledgeable people to help him.

He thought his knowledge would make his advice more persuasive.

小题3:What does the underlined phrase “the plain common sense” probably refer to?

That it was impossible for trees to grow on the wasteland.

That his normal work and life would be greatly affected.

That no one would like to join him in the efforts.

That he had to keep everything he did secret.

小题4:The message of the passage is that _____.

action speaks louder than words

perseverance(持之以恒) will work wonders

God helps those who help themselves

many hands make light work

判断题