问题 填空题

某中学化学实验室有如图所示的实验装置,用于制取氧气、二氧化碳等多种气体.

(1)请写出有标号仪器的名称:①       

(2)若制取的一种气体是    ,应选用的收集装置是    (填序号,下同),应选用的发生装置是  ,反应的化学方程式是       ;检验所制取的气体的方法是:                                       

(3)在常温下,用亚硫酸钠固体和稀硫酸制取二氧化硫气体,应选用的发生装置是:  ;由于二氧化硫是易溶于水、密度比空气大的有毒气体,所以应用  装置进行收集,以便将尾气吸收处理,避免造成        

(4)该中学化学课外兴趣小组同学利用发生装置B进行“石块中是否含有碳酸钙”的探究活动.在活动中小明发现,相邻小组气体产生的速率比自己小组的快.小明将这一情况报告老师,老师鼓励他们对此问题共同探究.

【提出问题】影响二氧化碳气体产生速率的因素是什么?

【作出猜想】①不同地点石块中碳酸钙含量不同;

②所用的盐酸不同;

③还可能是                    

【设计实验】(1)验证猜想①是否成立,要设计的实验:分别取大小相同、质量相同、            的石块,加入相同的稀盐酸进行实验.

【交流讨论】实验中可以通过观察              ,粗略地比较反应速率.

【拓展延伸】上述实验中,小明采用了控制单一变量的研究方法.用此方法探究“催化剂对用过氧化氢溶液制取氧气的反应速率的影响”,需要控制不变的因素有             等(答出一点即可).

答案

(1)试管;酒精灯;

(2)氧气;C或D;A;2KMnO4K2MnO4+MnO2+O2↑;

(3)B;E;大气污染;

(4)石块大小不同(或石块质量不同、盐酸质量不同);

不同地点;

放出气泡的剧烈程度不同;过氧化氢溶液的浓度、温度(合理均可).

题目分析:(1)依据常用仪器回答;

(2)若制取的是氧气,据氧气的密度和溶解性确定收集装置,并据制取氧气的方法书写方程式,选择发生装置;检验氧气用带火星的木条伸入瓶内,若木条复燃则是氧气;

(3)根据反应物状态和反应条件选择发生装置;并据二氧化硫的性质选择收集装置;

(4)【作出猜想】③从药品的表面积和酸的质量分数考虑;

【设计实验】(1)控制不同地点是石块这一个变量;

【交流讨论】实验中可以通过观察放出气泡的剧烈程度不同,粗略地比较反应速率;

【拓展延伸】从实验所需要的条件的考虑.

解:(1)标号仪器分别是试管和酒精灯;

(2)根据题意,这些装置可用于制取氧气和二氧化碳,若制取的是氧气,氧气的密度比空气大且不易溶于水,则可用向上排空气法或排水法收集;制取氧气可用加热高锰酸钾或氯酸钾的方法,分解过氧化氢溶液的方法,若用加热高锰酸钾的方法,属于固体加热型,则选A发生装置;反应方程式是2KMnO4K2MnO4+MnO2+O2↑;检验氧气用带火星的木条伸入瓶内,若木条复燃则是氧气;

(3)常温下,用亚硫酸钠固体和稀硫酸制取二氧化硫气体,不需加热,属于固液常温型,故选发生装置B;由于二氧化硫是易溶于水、密度比空气大的有毒气体,所以应用E收集,可将尾气用水吸收,防止污染大气;

(4)【作出猜想】③影响二氧化碳产生速率的因素还可能是:石块大小不同(或石块质量不同、盐酸质量不同);

【设计实验】(1)验证猜想①是否成立,要设计的实验:其他量都要相同,但要取不同地点的石块,进行实验;

【交流讨论】实验中可以通过观察气泡产生的剧烈程度,粗略地比较反应速率;

【拓展延伸】探究“催化剂对用过氧化氢溶液制取氧气的反应速率的影响”,需要控制不变的因素有 温度、溶液的溶质质量分数、溶液质量、压强等;

故答案为:(1)试管;酒精灯;

(2)氧气;C或D;A;2KMnO4K2MnO4+MnO2+O2↑;

(3)B;E;大气污染;

(4)石块大小不同(或石块质量不同、盐酸质量不同);

不同地点;

放出气泡的剧烈程度不同;过氧化氢溶液的浓度、温度(合理均可).

点评:掌握装置选取方法,反应原理,并能灵活应用解答问题,通过控制变量的方法研究化学问题是一种常用的方法,同学们要学会如何控制一个反应的变量,明确哪些变量可以控制等.

单项选择题
单项选择题

Children are a relatively modem invention. Until a few hundred years ago they look like adult, wearing grown-up clothes and grown-up expressions, performing grown-up tasks. Children did not exist because the family as we know it had not evolved.
Children today not only exist; they have taken over in no place more than in America, and at no time more than now. It is always Kids Country here. Our civilization is child-centered, child-obsessed. A kid’s body is our physical ideal. In Kids Country we do not permit middle-aged. Thirty is promoted over 50, but 30 knows that soon his time to be overtaken will come.
We are the first society in which parents expect to learn from their children. Such a topsy-turvy situation has come to abort at least in part because, unlike the rest of the world, ours is an immigrant society, and for immigrants the only hope is in the kids. In the Old Country, that is, Europe, hope was in the father, and how much wealth he could accumulate and pass along to his children. In the growth pattern of America and its ever- expanding frontier, the young man was ever advised to GO WEST; the father was ever inheriting from his son. Kids Country may be the inevitable result.
Kids Country is not at all bad. America is the greatest country in the world to grow up in because it is Kids Country. We not only wear kids clothes and eat kids food; we dream kids dreams and make them come tree. It was, after all, a boys’ game to go to the moon.
If in the old days children did not exist, it seems equally true today that adults, as a class, have begun to disappear, condemning all of us to remain boys and girls forever, jogging and doing push-ups against eternity.

The sentence "In Kids Country we do not permit middle-aged" underlined in Paragraph 2 means that middle-aged ______ .

A.are not permitted to live in America

B.are not welcome in America

C.become old too quickly

D.have already been overtaken by children