问题 问答题

用如图装置进行实验:

(1)可观察到两处明显的实验现象分别是:______,______.

(2)该实验说明了CO具有______性和______性.

(3)该装置一共发生4个化学反应,发生反应的化学方程式分别为______、______、______、______.

答案

(1)一氧化碳和氧化铜反应生成铜和二氧化碳,二氧化碳能使澄清的石灰水变浑浊,所以玻璃管中的黑色固体变红色,澄清石灰水变浑浊,故答案:玻璃管中的黑色固体变红色;澄清石灰水变浑浊;

(2)一氧化碳和氧化铜反应生成铜和二氧化碳说明一氧化碳具有还原性,尾气能点燃说明一氧化碳具有可燃性,故答案:还原性;可燃性;

(3)该过程中一氧化碳和氧化铜反应生成铜和二氧化碳、二氧化碳和氢氧化钙反应生成碳酸钙和水、一氧化碳和氧气点燃生成二氧化碳;二氧化碳和水还有碳酸钙反应生成碳酸氢钙;反应的化学方程式依次为CuO+CO

.
Cu+CO2;CO2+Ca(OH)2═CaCO3↓+H2O;O2+2CO
点燃
.
2CO2;CO2+H2O+CaCO3=Ca(HCO32

单项选择题
阅读理解

Last year, around Labor Day, I read a “Happy Ad” in our local newspaper. There was a lady in a local nursing home, who was celebrating her 90th birthday and her family wanted everyone to know about it. It said that if you wanted to drop her a line, here was her address. So I did. I found a birthday card and dropped her a short note, wishing her a happy birthday.

A week or so later, someone knocked at my front door. I opened the door and found a middle-aged man standing on my doorstep. He introduced himself as the son of this woman to whom I had sent the card. He explained that he just wanted to drop by in person and thank me for sending such a nice card to his mom. Apparently, like many older folks, she did not receive much mail and was quite excited to receive mine. I just didn’t know what to say. I told him it was my pleasure and that I hoped his mom had enjoyed her birthday.

That year, I did not send out any Christmas cards, except to this lovely old lady in the nursing home. I just told her that I was thinking about her and hoped that she had a nice holiday. I sent her a Valentine and also a couple of notes in between. I just thought she might like to have someone write to her, to get some mail.

She passed away a couple of months ago. I never met this lady, but I did keep her and her family in my thoughts. I dropped them a line of sympathy. I hope that my few little notes were enough to brighten a couple of her days here on earth.

小题1:The old lady’s address was given because ____________.

A.her family wanted to make her well-known

B.the old lady wanted to receive a birthday card

C.the son of the old lady wanted to meet the author

D.her family wanted to give her a happy birthday小题2:Which of the following best describes the author?

A.Brave.

B.Polite.

C.Caring.

D.Faithful.小题3:Which of the following is the best title for the passage?

A.A Kind Act

B.An Old Lady

C.A Happy Ad

D.A Considerate Son