问题 问答题

学完氧气的性质后,为加深对所学知识的认识,某同学设计了如下实验,根据实验你能回答有关问题吗?

(1)用排水法收集两瓶氧气(原理是______),正放在桌上备用.

(2)取一瓶氧气,倒立过来后再拿走玻璃片,并立刻把带火星的木条伸入瓶内(如图A所示),发现木条复燃,说明氧气具有______性.

(3)取另一瓶氧气,按图B的方式把带火星的木条伸入瓶内,木条也复燃了,且比A中更______说明______.

(4)下面是实验室制取和收集氧气的操作;(1)将高锰酸钾加入试管中,并用一团棉花放在靠近试管口的地方,然后用带导管的塞子塞紧;(2)用铁夹把试管固定在铁架台上;(3)检查装置的气密性;(4)加热试管;(5)用排水法收集氧气;(6)熄灭酒精灯;(7)实验完毕将导气管移出水面.其操作顺序正确的是______

A.(3)(1)(2)(4)(5)(7)(6)B.(3)(2)(1)(4)(5)(6)(7)

C.(2)(1)(3)(4)(5)(6)(7)D.(1)(2)(3)(4)(5)(6)(7)

(5)实验室用加热高锰酸钾制取和排水法收集氧气,实验完毕发现试管破裂,试分析造成试管破裂的可能原因是(至少写四点)

①______

②______

③______

④______.

答案

(1)实验室制氧气的方法有三种:分解过氧化氢溶液、加热氯酸钾、加热高锰酸钾,反应的化学方程式分别为:2H2O2 

 MnO2 
.
 
2H2O+O2↑、2KMnO4
  △  
.
 
K2MnO4+MnO2+O2↑、2KClO3
MnO2
.
2KCl+3O2↑;

故答案为:2H2O2 

 MnO2 
.
 
2H2O+O2↑;

(2)氧气具有助燃性,能使带火星的木条复燃;

故答案为:助燃;

(3)木条在B中燃烧比在A中燃烧更剧烈,说明氧气的密度比空气大;

故答案为:剧烈;氧气的密度比空气大;

(4)实验室用加热高锰酸钾的方法制取氧气,有如下操作步骤:检查装置的气密性;将高锰酸钾加入试管中,并用一团棉花放在靠近试管口的地方,然后用带导管的塞子塞紧;用铁夹把试管固定在铁架台上;加热试管;用排水法收集氧气;实验完毕将导气管移出水面;熄灭酒精灯,因此正确顺序为:(3)(1)(2)(4)(5)(7)(6);

故选A;

(5)根据实验室里用加热高锰酸钾的方法制氧气的实验操作步骤和注意事项进行分析:试管破裂可能是由于试管受热均匀,也可能是在高温时突然冷却等引起的.如试管没有预热,就直接加热会造成试管受热不均匀;试管口没有向下倾斜,实验完毕先停止加热再拿出水槽中的导管,这些都会导致水回流,试管破裂.

故答案为:①没有给试管均匀预热;②试管外壁有水滴;③试管口没有略向下倾斜;④实验完毕先停止加热后,再拿出水槽中的导管.

阅读理解

Making an apology is not the same as making amends. Sometimes we apologize just because it’s the easiest thing to do. What’s actually important is to identify where we go wrong, take full responsibility for our mistakes and , if possible, try to make up for them.

A recent case involving Hewlett-Packed, the US computer giant, shows the importance of presenting a sincere apology. The Chinese consumers who had bought notebook computers of certain models, which have been put on Chinese market since 2007, suffered a massive flash screen failures and overheating problems. Through investigation, Chinese AQSIQ(国家质检总局) identified these HP computers had quality problems and HP admitted this. HP made a proposal that they would extend the warranty period of such computers, but this could not satisfied the consumers. What they needed was a thorough description of the truth. HP has “sincerely” apologized. But the consumers remain angry, and say that only a product recall—as HP has done in the past—will prove that the apology is sincere.

Another apology that fell flat on its face was that of Thierry Henry, the famous French footballer. His deliberate handball in November 2009 created the goal which knocked Ireland out of the 2010 World Cup. The incident caused great anger in the football world, and eventually Henry issued and apology. Two days later, he wrote, “I’m not the referee…but if I hurt someone I’m sorry.” Better late than never, perhaps, but even then he passed the blame onto the referee!

Such high-profile cases, which attract a lot of publicity often under the spotlight, but similar incidents occur in our everyday lives. Stress caused by schoolwork and tiredness can sometimes result in outbursts of anger against friends and family. Have you ever lost your temper for minor reasons? After calming down, most people are quick to realize their mistake and apologize. But it’s just as important to identify what caused the error in the first place and take action to ensure it doesn’t happen again.

No one should hold a negative attitude to making a sincere apology. Empty words are easy to say, but they are as useless as they sound. A real show of remorse demands hard work and commitment to put error right. 

46. What does the author intend to tell us in the case of HP?

A. A true apology needs sincere actions.

B. HP should recall all the faulty computers.

C. Good quality makes a good company.

D. A company should apologize and pay for their mistakes.

47. According to the author, when we do anything wrong we firstly __________ .

A. make an apology face to face honestly

B. admit we were wrong and try to make the wrong right

C. take the responsibility for apologizing to others

D. choose the easiest thing to do

48. We can infer from the case of Thierry Henry that ______________ .

A. It’s never too late to say “I’m sorry.”

B. Writing an apology is not a good idea.

C. Henry didn’t identify his fault.

D. The football fans were mad with Henry.

49. Which of the following can best explain the word “commitment” in the last paragraph?

A. decision                B. promise             C. agreement                D. responsibility

50. What’s the best title of this passage?

A. What really puts things right                     

B. Don’t apologize easily

C. Making an apology—no one is out of exception

D. How to judge an apology—sincere enough?

填空题