问题 实验题

某化学兴趣小组同学进行如下实验。

(1)使用铜和稀硫酸制备硫酸铜晶体。步骤如下

步骤①观察到的现象是:______________________。

步骤③的主要操作包括:______________________。

(2)某同学查资料知:铜与稀硫酸不反应,若在稀硫酸中加入H2O2,铜可逐渐溶解。实验装置如图,写出该反应的化学方程式_____________________________

(3) 铜粉放入稀硫酸中,加热后无明显现象发生。当加入一种物质后,铜粉开始溶解,溶液变蓝色,同时有气体逸出,该物质是__________(填字母);      

A.Al2(SO4)3        B.Na2CO3    C.KNO3           D.FeSO4     

写出该反应的离子方程式_______________________。

答案

(1)红色固体变黑; 加热浓缩,冷却结晶,过滤

(2)Cu + H2O2 + H2SO4= CuSO+ 2H2O   

(3)C;3Cu + 8H+ 2NO3- =3Cu2+ + 4H2O + 2NO↑

问答题
阅读理解

It could happen to you

Many people think there is no need to take special care over home safety.

“I’ all right, I’m insured(投保).”

Maybe-----if you’re fully insured. Even then you can never recover the value you place upon your possessions, because you can’t insure against the suffering of mind that we all feel if our homes are torn apart by some strangers, our windows and doors broken, or our possessions ruined.

“It won’t happen to me.”

Won’t it? A house is broken into every three minutes of the day. Loss of all kinds, including cars and things stolen from cars, happens every 35 seconds.

“I’ve nothing worth stealing.”

You may think not. But in fact everyone has something worth a thief’s attention. And we all have things of personal value, even if they’re worth little or nothing inn hard cash.

“I’m only a tenant(房客) here.”

The thieves don’t care whether you’re a tenant or an owner. You’re just as weak either way. Have a word with the owner if you think extra safety fittings are necessary.

“They all get in anyway.”

Most thieves are on the lookout for easy pickings. They are soon discouraged by houses they can’t get into quickly and easily. So do pay special attention.

“This booklet(小册子) will help you…”

It’s based on the practical experience of police forces throughout the country. Most of the suggestions will cost you only a few minutes and thought. A few may cost some expense, but this is small compared with the loss and sadness you might otherwise suffer.

If you are in any doubt, ask for free advice from the crime Prevention Office at your local police station.

60. The passage is mainly about _____.

A. how to protect your home         B. how to take special care of ourselves

C. how to hire a safe house in the country     D. how to escape being caught 61. What does the sentence “A few may cost some expense” in the last two paragraphs mean?

A. You should pay for some of the suggestions.

B. Following the suggestions means you will have to spend some money on home protection.

C. some people are willing to pay for the suggestions.

D. Some of the suggestions are expensive.

62. Which of the following statements is TRUE according to the passage?

A. It’s impossible to prevent a house from being broken into.

B. Few people would like to get advice from the local police station.

C. Some thieves are only interested in stealing things from houses protected well.

D. People should care more about home safety.

63. This passage is probably a (an) _____.

A. advertisement for selling safely-guarded houses             

B. article on crime

C. booklet from the Crime Prevention Office

D. suggestion from insurance companies