问题 实验题

为了证明在实验室制备Cl2的过程中会有水蒸气和HCl挥发出来,甲同学设计了如图所示的实验装置,按要求回答问题:

(1)请根据甲同学的意图,连接相应的装置,接口顺序:b接             

          

(2)U形管中所盛试剂的化学式为               

(3)装置③中CCl4的作用是            

(4)乙同学认为甲同学实验有缺陷,不能证明最终通入AgNO3溶液中的气体只有一种,为了确保实验结论的可靠性,证明最终通入AgNO3溶液的气体只有一种,乙同学提出在某两个装置之间再加装置⑤。你认为装置⑤应加在               之间(填装置序号)。瓶中可以放入                              

(5)丙同学看到甲同学设计的装置后提出无需多加装置,只需将原来烧杯中的AgNO3溶液换成其他溶液。你认为可将溶液换成           ,如果观察到         现象,则证明制Cl2时有HCl挥发出来。

答案

(1)e  f  d  c  a(或f  e  d  c  a)(2) 无水CuSO4 (3)吸收Cl2  

(4)③① 淀粉KI溶液   (5)紫色石蕊试液   紫色石蕊试液变红而不退色

题目分析:(1)先验证制备的氯气中是否含有水蒸气,然后除去氯气,再检验是否含有氯化氢,所以相应的装置接口连接顺序为b,e,f,d,c,a。

(2)无水硫酸铜与水反应生成蓝色五水硫酸铜晶体,可用来检验水,即U形管中所盛试剂的化学式为CuSO4

(3)氯气易溶于四氯化碳溶液,可用来吸收氯气,防止干扰HCl检验。

(4)①装置用来检验HCl气体,为了确保实验结论的可靠性,应排除氯气的干扰,在③吸收氯气之后要检验氯气是否完全除去,根据氯气具有强氧化性的性质,可用湿润的淀粉KI试纸检验,如不变色,说明已经完全除去。

(5)HCl呈酸性,使紫色石蕊试液变红,Cl2使紫色石蕊试液先变红后褪色.若只变红不褪色,说明制Cl2时有HCl挥发出来。

点评:本题以氯气的制备和性质的检验为载体,考查学生对实验方案设计评价,题目综合性较强合,难度中等。答题时关键理清实验原理和目的及各装置的作用,有利于培养学生规范严谨的实验设计能力和创新思维能力。

单项选择题

Regardless of their political affiliation, in all countries women must overcome a host of stumbling blocks that limit their political careers. "Most obstacles to progress consist of (1) of various kinds," says the Inter-Parliamentary Union (IPU), a Geneva-based organization (2) 139 parliaments, including the lack of time, training, information, self-confidence, money, support, motivation, women’s networks and solidarity between women.

In every culture, prejudice and stereotypes (3) hard. The belief still holds (4) that women belong in the kitchen and (5) the children, not at election (6) or in the Speaker’s chair. The media often reinforce traditional images of women, who, upon entering politics, also bear the brunt (正面冲击) of verbal and physical (7) .

In impoverished (贫穷的) countries (8) by civil conflicts and deteriorating economic and social conditions, women are (9) by the tasks of managing everyday life and looking after their families.

The IPU stresses the general lack of child-care facilities—often (10) a privileged few—the (11) of political parties to change the times and running of meetings and the weak backing women receive from their families. That support, which is (12) as well as financial, is (13) vital because women have internalized (14) images of themselves since the (15) of time and often suffer from low self-confidence.

Another obstacle is the lack of financial resources, especially as election campaigns become increasingly expensive. (16) , women encounter more or less open machismo (男子汉的高傲) in the (17) of closed political circles (18) entry to the "second sex. " Lastly, they (19) the lack of solidarity between women, (20) by the fact that the number of available positions is limited.

12()

A.moral

B.mortal

C.orthodox

D.sensible

单项选择题