问题 实验题

氮及其化合物在生产、生活中有重要的作用。

(1)NH3是制碱工业中不可缺少的重要物质。继侯德榜“联合制碱法”后,上世纪50年代某些化工专家开始研究有机胺制碱法,其工艺流程如下:

已知:NR3 + CO2 + NaCl + H2O = NaHCO3 + NR3·HCl

NR3 + HCl = NR3·HCl,且NR3·HCl 易溶于有机溶剂。

①操作Ⅰ名称为                 

②某实验小组同学查阅资料知,有机溶剂和有机胺沸点差别较大,现欲将A中各成分进行分离,请写出除了导管、酒精灯、牛角管、锥形瓶外,该分离操作所需的玻璃仪器名称                     

(2)N2在化工生产、农业、医疗、航天航空等领域用途广泛。现提供以下装置(连接仪器略去):

①某化学兴趣小组甲同学欲用加热NaNO2 和NH4Cl的浓溶液制得N2,应该选择的发生装置是        ,检验该发生装置气密性的操作为                                              

②在加热条件下,用NH3 还原CuO可制得N2,同时获得铜粉,此反应的化学方应方程式是                                 。乙同学用此法制得干燥、纯净的N2,且需要的NH3 以生石灰和浓氨水作原料。按气流从左到右,整套装置的连接顺序是                (填写字母序号);最后一个装置中试剂的作用是                                 ;

答案

(1)①分液(2分)

②蒸馏烧瓶、温度计、冷凝管(2分,答对2种得1分,全答对得2分)

(2)①A (2分);关闭分液漏斗下端活塞并将导管连接长导管后置于水中(1分),用酒精灯微热圆底烧瓶,若导管口有气泡冒出,撤掉酒精灯后导管内有一段水柱,则装置气密性好(1分);反之,则装置气密性不好。

②3CuO+ 2NH3N2+ 3Cu + 3H2O(2分);DEBC(2分);干燥N2(1分)并除去其中的NH3(1分)

题目分析:(1)①分离互补相溶液体的方法是分液,所以操作Ⅰ名称为分液。

②有机溶剂和有机胺沸点差别较大,可用蒸馏分离,根据蒸馏的仪器:带铁圈的铁架台,酒精灯,石棉网,蒸馏烧瓶,温度计,冷凝管,牛角管,锥形瓶,因此还缺少蒸馏烧瓶、温度计、冷凝管。

(2)①根据已知信息可知,反应物是亚硝酸钠(NaNO2)和氯化铵的浓溶液混合加热制备氮气,所以需要圆底烧瓶作反应容器,同时还需要加热,因此A装置适合;检验装置气密性的方法一般是利用压强差来进行,所以正确操作是安装好仪器后,关闭分液漏斗下端活塞并将导管连接长导管后置于水中,用酒精灯微热圆底烧瓶,若导管口有气泡冒出。撤掉酒精灯后导管内有一段水柱,则装置气密性好;反之,则装置气密性不好。

②根据原子守恒可知,NH3与CuO反应生成N2、铜和水,所以反应的化学方程式为3CuO+ 2NH3N2+ 3Cu + 3H2O;需要的NH3 以生石灰和浓氨水作原料,因此需要用D用来制取氨气,氨气是碱性气体,不能用浓硫酸干燥,应该用E装置(碱石灰)干燥氨气。在B中反应后,剩余的氨气可用C装置来除去,同时C装置中的浓硫酸还能干燥氮气。所以按气流从左到右,整套装置的连接顺序是DEBC。

选择题
单项选择题

Who won the World Cup 1994 football game What happened at the United Nations How did the critics like the new play (1) an event takes place, newspapers are on the streets (2) the details. Wherever anything happens in the world, reporters are on the spot to (3) the news.
Newspapers have one basic (4) , to get the news as quickly as possible from its source, from those who make it to those who want to (5) it.
Radio, telegraph, television, and (6) inventions brought competition for newspaper. So did the development of magazines and other means of communication. (7) , this competition merely spurred the newspapers on. They quickly made use of the newer and faster means of communication to improve the (8) and thus the efficiency of their own operations. Today more newspapers are (9) and read than ever before. Competition also led newspapers to branch out into many other fields. Besides keeping readers (10) of the latest news, today’s newspapers (11) and influence readers about politics and other important and serious matters. Newspapers influence readers’ economic choices (12) advertising. Most newspapers depend on advertising for very (13) .
Newspapers are sold at a price that (14) even a small fraction of the cost of production. The main (15) of income for most newspapers is commercial advertising. The (16) in selling advertising depends on a newspaper’s value to advertisers. This (17) in terms of circulation. How many people read the newspaper
Circulation depends (18) on the work of the circulation department and on the services or entertainment (19) in a newspaper’s pages. But for the most part, circulation depends on a newspaper’s value to readers as a source of information (20) the community, city, county, state, nation, and world—and even outer space.

[A] source [B] origin [C] course [D] finance